Know: How Much Does A Yard Of Salt Weigh Accurately

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Know: How Much Does A Yard Of Salt Weigh Accurately

How much does a yard of salt weigh accurately? A cubic yard of salt, like the kind used for roads or deicing, typically weighs between 2,000 and 2,700 pounds. This range exists because many things change how much salt fits in that space, mainly the type of salt, how much water is in it, and how tightly it’s packed. So, while we often talk about a typical weight of a yard of salt, it’s important to know it’s not one exact number every time.

What a “Yard” of Salt Means

When people talk about buying or using a “yard” of salt, they usually mean a cubic yard.

Defining a Cubic Yard

A cubic yard is a measure of space. It’s like a box that is 3 feet long, 3 feet wide, and 3 feet high.

• Imagine a cube.
• Each side of the cube is 3 feet long.
• The amount of stuff that fits inside this cube is one cubic yard.

We use this term for things sold in bulk, like dirt, mulch, sand, or salt. It measures the volume, or how much space the material takes up.

Volume vs. Weight

Volume is about space. Weight is about how heavy something is.

• Think about a box. It has a certain amount of space inside (its volume).
• What you put in the box makes it heavy (its weight).
• A box full of feathers takes up the same space as a box full of rocks, but the box of rocks is much heavier.
• This is because rocks are much denser than feathers.
• Density is how much weight is packed into a certain amount of space.

For salt, a cubic yard is a set amount of space. But the actual weight of cubic yard of rock salt can change. This is because the density of the salt changes.

Typical Weight of a Yard of Salt

The exact weight of a cubic yard of salt is not always the same. It can be different each time you measure it.

What Salt is Used

Often, the salt talked about is rock salt. This is salt dug out of the ground. It is the most common kind of salt used to melt ice on roads.

• This kind of salt has crystals.
• The crystals are not all the same size.
• They are not perfectly shaped.

The General Weight Range

For rock salt, a cubic yard usually weighs somewhere between 2,000 and 2,700 pounds.

• This is a wide range.
• 2,000 pounds is 1 ton.
• So, a yard of rock salt can weigh between 1 ton and about 1.35 tons.
• This is the typical weight of a yard of salt when we talk about rock salt for winter use.

Why is There a Range?

The weight is not fixed. It changes because of simple things. We will look at what makes the weight change. This explains why knowing the exact bulk salt weight needs more details.

Factors Affecting Salt Weight

Many simple things can change how much a cubic yard of salt weighs. These things change the salt’s density. Density is how much stuff is packed into a certain space.

Moisture Content

This is one of the biggest reasons the weight changes. Salt loves water. It pulls water from the air.

• Salt crystals naturally have small amounts of water.
• Salt stored outside gets wet from rain or snow.
• Even salt stored inside can pull water from wet air.

Water is heavy.

• If salt has more water in it, the total weight of the same amount of salt (one cubic yard) goes up.
• Think of a sponge. A dry sponge is light. A wet sponge is heavy.
• Salt works a bit like that.
• Salt that is very dry might weigh close to 2,000 pounds per cubic yard.
• Salt that is wet from rain could weigh much more, maybe up to 2,700 pounds or even more.
• The deicing salt weight you get might depend a lot on how wet it is when you buy it.

Particle Size and Shape

Salt crystals are not perfect squares or circles. They have different shapes and sizes.

• Think of filling a box with marbles. They are round. There will be spaces between them.
• Now think of filling the same box with sand. The smaller, irregular pieces of sand fit together more tightly. There are fewer empty spaces.
• The box of sand will weigh more than the box of marbles, even if they fill the same space.

Salt crystals are like this.

• Rock salt crystals can be big or small.
• They have rough edges.

• How they pack together changes the weight.

• If the salt has a mix of big and small pieces, the small pieces can fill the gaps between the big ones. This makes the salt pack together more densely. It will weigh more per cubic yard.

• If the salt crystals are all about the same size, they might not pack as tightly. There will be more air spaces. This makes the salt weigh less per cubic yard.
• The shape of the crystals also matters. Rough, sharp edges can prevent them from settling closely together compared to smoother shapes.

Compaction

How much the salt is pressed down changes its density.

• Think of putting clothes in a suitcase. If you just throw them in, they take up a lot of space. If you press them down, you can fit more in.

• Salt works like this too.

• Salt that is just piled up loosely will have a lot of air pockets. It won’t be very dense. It will weigh less per cubic yard.

• Salt that has been sitting in a pile for a long time, or has had heavy machines drive over it, gets pressed down. The air pockets are squeezed out. The salt becomes more dense. It will weigh more per cubic yard.
• This is why the density of salt in a big storage pile can be higher than the density of salt that was just loaded onto a truck.
• The way a truck is loaded can also affect compaction. Dropping salt from high up can cause it to compact more at the bottom of the truck bed.

Type of Salt

Not all salt is the same. There are different types, and they have different densities and crystal shapes.

• Rock Salt: This is dug from the earth. It’s usually coarse and not pure white. It’s the most common for roads. Its typical weight range is 2,000-2,700 lbs per cubic yard. This is the main type we are discussing when we talk about how much does road salt weigh or deicing salt weight.
• Evaporated Salt (or Solar Salt): This salt is made by letting salty water (like from the sea) dry up in shallow ponds. The crystals are often more uniform and cleaner. This type might have a slightly different density than rock salt.
• Water Softener Salt: This is often evaporated salt, sometimes pressed into pellets or cubes. These shapes pack differently than loose crystals. Pellets or cubes might pack loosely, leading to a lower density and lower weight per cubic yard compared to rock salt.
• Fine Salt: Very fine salt (like table salt, but larger amounts). Smaller particles can sometimes pack very tightly if dry, but can also clump easily if wet. Its density might be different.

The specific type affects the natural shape and size of the crystals. This changes how they fit together and the salt weight per cubic foot (and thus per cubic yard).

Additives

Sometimes things are added to salt.

• Anti-caking agents are sometimes added to rock salt. These are chemicals that help stop the salt crystals from sticking together and forming hard clumps.
• These additives are usually a very small amount of the total weight.
• They don’t change the overall weight per cubic yard very much, but they can affect how well the salt flows or how it settles, which can slightly influence compaction.

Weighing Salt: Volume vs. Weight

When you buy salt in bulk, you might buy it by the yard (volume) or by the ton (weight). Knowing the approximate weight per yard is important if you buy by volume.

Buying by the Yard

• You order a certain number of cubic yards.
• The truck or loader bucket is measured to hold a certain volume, like 3 cubic yards or 5 cubic yards.
• You pay for the space the salt fills.
• But what you care about for melting ice is the amount of salt, which relates to its weight.
• If you get a wet, compacted yard, you get more actual salt (by weight) than if you get a dry, loose yard, even though the volume is the same.
• This is why understanding the typical weight of a yard of salt and the things that change it is useful. You have a better idea of how much melting power you are getting.

Buying by the Ton

• You order a certain number of tons.
• The truck is weighed before the salt is loaded and after.
• You pay for the exact weight of the salt.
• This is a more accurate way to know how much salt you are getting.

Most large buyers of bulk salt weight buy it by the ton because it’s a more exact measure of quantity. Smaller buyers, like homeowners or small businesses, often buy by the cubic yard.

Calculating Salt Weight and Conversions

We can talk about salt weight in different ways. We can talk about a cubic yard, a cubic foot, or even how many pounds are in a ton.

Cubic Yard Salt Pounds

We know a cubic yard of rock salt is usually between 2,000 and 2,700 pounds.

• This gives us the range for cubic yard salt pounds.
• Let’s take an average or typical number for calculation examples.
• A common figure used is around 2,400 pounds per cubic yard for average conditions.
• So, 1 cubic yard ≈ 2,400 pounds.

Salt Weight Per Cubic Foot

A cubic yard is a big cube made of 27 smaller cubic feet.

• Think of the 3x3x3 box again. 3 feet * 3 feet * 3 feet = 27 cubic feet.
• So, to find the weight of just one cubic foot, we take the weight of the cubic yard and divide by 27.

If 1 cubic yard weighs 2,400 pounds:
* Weight per cubic foot = Weight per cubic yard / 27
* Weight per cubic foot = 2,400 pounds / 27
* Weight per cubic foot ≈ 88.96 pounds

So, the salt weight per cubic foot is roughly 89 pounds when the cubic yard weight is 2,400 pounds.

If the cubic yard weighs 2,000 pounds:
* Weight per cubic foot = 2,000 pounds / 27
* Weight per cubic foot ≈ 74.07 pounds

If the cubic yard weighs 2,700 pounds:
* Weight per cubic foot = 2,700 pounds / 27
* Weight per cubic foot = 100 pounds

So, the salt weight per cubic foot typically ranges from about 74 to 100 pounds, depending on the factors we talked about.

Density of Salt

Density is weight per unit of volume. We just calculated this!

• The density of salt in pounds per cubic foot is the same number as the salt weight per cubic foot.
• For rock salt, the bulk density is usually between 74 and 100 pounds per cubic foot.
• The density of a single, solid salt crystal (without any air gaps) is much higher, around 135 pounds per cubic foot. But when you have a pile of crystals, there is always air space between them. The “bulk density” is what matters for a cubic yard.

Salt Weight Conversion

Knowing the weight per cubic yard helps with conversions.

• 1 ton = 2,000 pounds.
• If a cubic yard weighs 2,400 pounds, it’s more than a ton.
• To find out how many tons are in a cubic yard:
  • Tons = Pounds / 2,000
  • Tons = 2,400 / 2,000 = 1.2 tons

So, 1 cubic yard of salt weighing 2,400 pounds is equal to 1.2 tons of salt.

• If you buy 10 cubic yards and each yard weighs 2,400 pounds:
  • Total pounds = 10 * 2,400 = 24,000 pounds
  • Total tons = 24,000 / 2,000 = 12 tons

This salt weight conversion is very important for planning. If you need a certain amount of salt in tons for a job, but you buy it by the yard, you need to estimate the weight per yard to figure out how many yards to buy.

Here is a simple table showing conversions based on a typical weight:

Table: Approximate Salt Conversions (Assuming 2400 lbs/yd³)

Unit	Weight in Pounds	Weight in Tons
1 Cubic Foot	~89 pounds	~0.044 tons
1 Cubic Yard	~2400 pounds	~1.2 tons
1 Ton (2000 lbs)	2000 pounds	1 ton
1 Short Ton	2000 pounds	1 ton
1 Metric Ton	~2205 pounds	~1.1 tons

Note: These are approximate based on one assumed typical density. Actual weights will vary.

How Much Does Road Salt Weigh?

How much does road salt weigh? Road salt is usually rock salt. So, its weight per cubic yard falls into the typical range for rock salt.

• A cubic yard of road salt generally weighs between 2,000 and 2,700 pounds.
• This weight depends heavily on how much water is in it and how much it was packed down in storage or during loading.
• Salt delivered during or right after wet weather will likely be on the heavier side of this range.
• Salt delivered dry from a protected storage might be on the lighter side.

Deicing Salt Weight

Deicing salt weight is also talking about road salt or very similar types used to melt ice.

• Whether it’s called road salt, ice melt salt, or deicing salt, if it’s bulk rock salt, the same weight factors apply.
• The weight of a cubic yard will still be in the 2,000 to 2,700 pound range.
• Sometimes, specialized ice melts contain additives or are different types of salt (like calcium chloride or magnesium chloride mixes). These might have different densities than pure rock salt. However, bulk purchases for roads are overwhelmingly rock salt.

So, when you’re dealing with typical winter deicing or road salt, expect the weight per cubic yard to be within that common range, shifting based on how wet or packed the salt is.

Grasping the Factors Affecting Weight More Deeply

Let’s look a little closer at why these factors make such a difference in the bulk salt weight.

Interpreting Moisture’s Impact

Water is about 62.4 pounds per cubic foot.

• Salt’s bulk density is around 74-100 lbs/cubic foot when considering air gaps.
• If water fills some of the air spaces between salt crystals, it adds weight.
• Imagine the space between salt crystals. If some of that space fills with water instead of air, the total weight of that cubic foot (or cubic yard) goes up a lot, because water is much heavier than air.
• Salt also pulls water into its crystal structure in a process called hygroscopy. This adds weight directly to the crystal itself.
• Wet salt clumps together more easily. This can affect how it flows and how it compacts in a pile or truck. Clumping can sometimes create larger voids, or if heavy, cause more settling and compaction lower down.

This is why a pile of salt left outside in the rain gets heavier and might start to look like a solid mass near the bottom.

Fathoming Particle Size and Shape Differences

Think about trying to fit things into a jar.

• If you use large, round marbles, you can see big gaps between them.
• If you use small, round beads, there are still gaps, but they are smaller.
• If you use sand (small, irregular shapes), the pieces fit together quite well, leaving less empty space.

Rock salt has many different crystal sizes and shapes.

• Some salt comes “screened” or “graded,” meaning the pieces are sorted by size. This can lead to less tight packing if all pieces are similar.
• Mixed sizes, like from a mine run, tend to pack more densely because smaller pieces fill spaces between larger ones. This increases the density of salt.
• The shape of the crystals also matters. Rough, sharp edges can make crystals ‘bridge’ over each other, leaving voids underneath. Smoother crystals might settle more easily.

Deciphering Compaction Effects

Compaction reduces the amount of air in the salt volume.

• When salt is first dumped, it’s loose. There’s a lot of air between the crystals.
• As more weight is put on top (a taller pile) or as time passes, the salt settles. The crystals shift closer together. Air is pushed out.
• This makes the salt at the bottom of a large pile much denser and heavier per cubic foot than the salt at the top of the pile.
• Using heavy machinery to move or stack salt also compacts it.

So, the salt weight per cubic foot isn’t just about the salt itself, but how much air is mixed in with it in that space.

Why Knowing the Weight Matters

Knowing the approximate weight of cubic yard of rock salt is important for several practical reasons.

Budgeting and Buying

• If you buy salt by the yard, but plan how much you need by weight (e.g., “I need 50 tons for the winter”), you need to estimate the weight per yard.
• Using a figure like 2,400 lbs/yard helps you estimate how many yards you need. 50 tons * 2000 lbs/ton = 100,000 lbs. 100,000 lbs / 2,400 lbs/yard = ~41.7 yards. You might order 42 or 43 yards.
• If the salt is heavier (say, 2,700 lbs/yard), you would get more weight per yard than you budgeted for using the lower number. 100,000 lbs / 2,700 lbs/yard = ~37 yards. You could potentially buy less volume to get the same weight.
• If the salt is lighter (say, 2,100 lbs/yard), you would get less weight. 100,000 lbs / 2,100 lbs/yard = ~47.6 yards. You might need to buy more yards than planned.
• This difference can affect your budget and how much storage space you need.

Logistics and Transport

• Trucks have weight limits. A standard dump truck might be able to carry 10-15 tons safely.
• If a cubic yard weighs 2,400 pounds (1.2 tons), a 10-ton load would be about 8.3 cubic yards (10 / 1.2).
• If the salt is very wet and weighs 2,700 pounds (1.35 tons) per yard, a 10-ton load is only about 7.4 cubic yards (10 / 1.35).
• This means a truck can carry less volume of wet, heavy salt than dry, lighter salt while staying within its weight limit.
• Knowing the salt weight conversion is key for transport planning. You might need more truckloads for the same volume of wet salt compared to dry salt.

Spreader Calibration

• Salt spreaders are often calibrated to spread a certain amount of salt per acre or per mile.
• This amount is usually measured by weight (e.g., 300 pounds per acre).
• To calibrate a spreader that measures volume (like by auger turns), you need to know the weight of the salt you are using.
• If your salt weighs 2,400 pounds per yard (89 lbs/cubic foot), a certain auger setting will deliver a known weight.
• If you switch to salt that weighs only 2,100 pounds per yard (78 lbs/cubic foot), that same auger setting will deliver less weight of salt.
• You might need to adjust your spreader settings based on the deicing salt weight of the batch you are using to apply the correct amount.

Storage Space

• If you buy salt by the ton but store it in a space that limits volume (like a shed or bin), you need to know how much space a ton takes up.
• Using the conversion, if 1 ton is 2000 pounds and a yard is 2400 pounds (1.2 tons), then 1 ton is slightly less than a cubic yard.
• Specifically, 1 ton (2000 lbs) / 2400 lbs/yard = 0.83 cubic yards.
• So, 1 ton of salt takes up about 0.83 cubic yards of space if its density means a yard weighs 2400 pounds.
• If the salt is very light (2000 lbs/yard), then 1 ton takes up exactly 1 cubic yard.
• If the salt is very heavy (2700 lbs/yard), then 1 ton takes up only 0.74 cubic yards (2000 / 2700).
• This helps you figure out how much storage volume you need for the total weight of salt you plan to buy.

More Details on Factors

Let’s break down the main things that change the weight a bit more simply.

Water Makes it Heavy

Salt is chemically made of Sodium (Na) and Chlorine (Cl) – NaCl. It pulls water.

• Humid air has water in it. Salt crystals can grab this water.
• The little gaps between salt crystals in a pile can also fill with water if the salt gets rained on or sits on wet ground.
• Water molecules are heavy for their size compared to air molecules.
• Putting water into the spaces where air used to be makes the total volume (the cubic yard) weigh more.
• This is the main reason why the weight of cubic yard of rock salt changes so much from day to day or season to season.

Crystal Shape and Packing

Think about stacking things neatly versus just dropping them.

• Cube shapes can stack neatly with little space between them.
• But salt crystals are not perfect cubes. They are jagged.
• Jagged pieces don’t fit together perfectly. They leave spaces.
• A mix of sizes fills more space than all one size. Imagine mixing big rocks and small pebbles – the pebbles fill gaps between the rocks.

This is how the salt weight per cubic foot changes based on the mix of crystal sizes and their natural shape.

Squeezing Out Air

Compaction is simply removing air from the salt pile.

• When salt is delivered, it fluffs up a bit. It has a lot of air caught between the crystals.
• Gravity pulls the salt down over time, especially in a tall pile. This squeezes the bottom layers.
• Machines driving on the pile also squeeze it.
• This squeezing means more salt crystals are forced into the same amount of space.
• More salt crystals in the same space = higher density = more weight for that cubic yard.

Knowing these factors affecting salt weight helps explain why measuring by weight (tons) is more exact than measuring by volume (yards) if you need a precise amount of salt.

Typical Weights in Different Situations

Here are some rough numbers you might see for bulk salt weight in a cubic yard under different conditions:

• Very Dry, Loose Salt: Might be on the lighter side, around 2,000 to 2,200 pounds per cubic yard.
• Average Condition Salt: This is often assumed for estimates, around 2,300 to 2,500 pounds per cubic yard.
• Wet Salt: Salt that has been exposed to rain or is very humid can be heavier, from 2,500 up to 2,700 pounds or more per cubic yard.
• Heavily Compacted Salt: The salt at the bottom of a large, old pile could be very dense and weigh at the high end of the range, or even slightly over 2,700 pounds per cubic yard.

These are just guides. The exact weight must be measured.

How to Measure Accurately

The only way to know the weight of salt in a cubic yard for sure is to measure it.

• Fill a container that you know is exactly one cubic yard in volume.
• Weigh the empty container.
• Fill the container with the salt you want to measure.
• Weigh the full container.
• Subtract the weight of the empty container.
• The number you get is the accurate weight of that specific cubic yard of salt.

However, this is not practical for large amounts. When buying in bulk, you rely on the supplier.

• If you buy by the ton, the supplier weighs the truck. This gives you an accurate measure by weight.
• If you buy by the yard, the supplier measures the volume loaded. The weight is then an estimate based on their typical bulk salt weight or your knowledge of its condition (wet or dry).

Comparing Salt to Other Materials

It helps to compare salt’s weight to other things sold by the yard.

Table: Approximate Weights Per Cubic Yard

Material	Typical Weight Range (Pounds per Cubic Yard)
Topsoil	2,000 – 2,700
Sand (Dry)	2,400 – 2,800
Sand (Wet)	2,700 – 3,100
Gravel	2,400 – 3,000
Mulch (Wood)	400 – 800
Concrete	~4,050
Rock Salt	2,000 – 2,700

• This table shows that dry rock salt can be lighter than dry sand or gravel.
• But wet rock salt is in a similar weight range to dry sand or topsoil.
• Concrete is much heavier. Mulch is much lighter.

This comparison puts the typical weight of a yard of salt into perspective compared to other common bulk materials.

Salt Purity and Weight

The purity of the salt can also slightly affect its density.

• Rock salt is a natural product. It’s dug from the ground.
• It can contain small amounts of other minerals or clay.
• These other materials might have different densities than pure salt (NaCl).
• A higher amount of impurities could slightly change the overall bulk density and therefore the weight per cubic yard.
• However, for standard road salt, the purity is usually high enough that this is a minor factor compared to moisture or compaction.

Summary of Weight Factors

To quickly review the factors affecting salt weight:

• Moisture: More water makes salt heavier per cubic yard. This is often the biggest factor.
• Particle Size/Shape: How well crystals pack together changes the amount of air space. Mixed sizes usually pack better.
• Compaction: Squeezing air out of the salt pile makes it denser and heavier.
• Salt Type: Different types (rock salt, solar salt) have slightly different crystal properties.
• Additives/Purity: Usually minor effects on weight for bulk rock salt.

These factors explain the range of cubic yard salt pounds you might encounter.

Practical Tips for Dealing with Salt Weight

• When buying by the yard: Ask your supplier about the salt’s condition. Is it fresh from storage? Has it been rained on? This helps you guess if it’s likely to be on the lighter or heavier side of the range.
• When budgeting: Use an average number (like 2,400 lbs/yd³) for planning, but be aware that the actual weight could be lower or higher. It’s safer to budget for a slightly heavier weight if storage or truck weight limits are critical.
• For critical needs (like large operations): Buy salt by the ton. This is the most accurate way to purchase salt quantity by weight.
• Storage: Store salt under cover if possible to keep moisture out. This prevents it from getting heavier (saving on transport if you buy by weight) and also helps prevent clumping.
• Know your equipment: Understand the volume capacity of your loader buckets and truck beds. Use estimated weight per volume (salt weight per cubic foot or yard) to estimate how much weight you are loading. Don’t overload trucks.

By keeping these factors in mind, you can have a better idea of how much a yard of salt weighs and plan accordingly.

Frequently Asked Questions

How much does a yard of rock salt weigh?

A cubic yard of rock salt typically weighs between 2,000 and 2,700 pounds. The exact weight changes based on how much water is in the salt and how tightly it is packed.

Is a yard of salt a ton?

Not usually exactly. A yard of salt is a measure of volume. A ton is a measure of weight (2,000 pounds). While a yard of salt can weigh around a ton (sometimes less, often more), they are not the same thing. A typical yard weighs closer to 1.2 tons.

What affects the weight of bulk salt?

Many things change bulk salt weight. The main ones are the amount of moisture in the salt, the size and shape of the salt crystals, and how much the salt has been squeezed or compacted in its pile.

How many pounds are in a cubic foot of salt?

The salt weight per cubic foot changes depending on the salt’s density. For rock salt, it is usually between about 74 pounds and 100 pounds per cubic foot. This is found by dividing the weight of a cubic yard by 27 (because there are 27 cubic feet in a cubic yard).

What is the density of salt?

The bulk density of salt (like in a pile) is its weight per cubic foot. For rock salt, this is typically between 74 and 100 pounds per cubic foot. This is lower than the density of a single, solid salt crystal because a pile of salt has air gaps.

Why does wet salt weigh more?

Water is much heavier than air. When water gets into the spaces between salt crystals, it adds weight to the total volume. Salt also pulls water into its crystals, adding even more weight.

How does the type of salt affect its weight?

Different types of salt (like rock salt vs. solar salt) can have different crystal shapes and sizes. This changes how tightly the crystals pack together, which changes the amount of air space and affects the salt weight per cubic foot (and cubic yard).

How do I convert cubic yards of salt to tons?

You need to know the weight per cubic yard first. Once you have that, divide the total pounds by 2,000 (since 1 ton = 2,000 pounds). For example, if you have 5 cubic yards and each yard weighs 2,400 pounds, the total weight is 12,000 pounds. 12,000 pounds / 2,000 pounds/ton = 6 tons. This is the salt weight conversion.

Is how much does road salt weigh the same as deicing salt weight?

Yes, for typical bulk salt used to melt ice on roads, these terms mean the same thing. Both refer to rock salt, and the factors affecting its weight per cubic yard are the same, resulting in the typical 2,000-2,700 pound range per cubic yard.

Can compaction really change the weight much?

Yes. Squeezing air out of the salt pile means more salt crystals fit into the same space. This increases the density of salt and makes a cubic yard weigh more. Salt at the bottom of a tall pile is often heavier per cubic yard than salt at the top.

Knowing the factors that influence how much does a yard of salt weigh accurately helps you make better choices when buying, storing, and using salt for winter. While 2,000 to 2,700 pounds is the usual range for a cubic yard of rock salt, remembering moisture and packing are key to why the exact number changes.