Image Source: images.thdstatic.com
Find Out How Many 60lb Bags Of Concrete Are In A Yard
You need to know how many 60lb concrete bags make up a cubic yard. A cubic yard is a big measure of space. It is 3 feet wide, 3 feet long, and 3 feet deep. Most people doing home projects buy concrete in bags. Knowing how many bags you need is key. It saves you money. It stops you from buying too much or too little. For a 60lb bag of concrete, you typically need about 45 bags to get one cubic yard of concrete. This number can change a little. It depends on the exact mix and how wet it is. But 45 bags is a very good number to start with for your plans. This number tells you the number of concrete bags per yard when using 60lb bags.
What is a Cubic Yard?
Let’s think about what a cubic yard of concrete means. Imagine a box. This box is 3 feet wide. It is also 3 feet long. It is 3 feet high or deep. The space inside this box is one cubic yard. Think of it like this:
- Length = 3 feet
- Width = 3 feet
- Height = 3 feet
To find the volume, you multiply these numbers. 3 feet * 3 feet * 3 feet = 27 cubic feet. So, one cubic yard is the same as 27 cubic feet. This is the amount of space we need to fill with concrete. When you pour a patio or a walkway, you need a certain volume of concrete. Often, this volume is measured in cubic yards. Big trucks bring ready-mix concrete in cubic yards. But for smaller jobs, bags are easier.
Figuring Out Concrete Bag Volume
Concrete comes in bags. These bags hold dry mix. You add water to make wet concrete. Each bag makes a certain amount of wet concrete. This amount is called the concrete bag yield. It tells you how much volume does a bag of concrete cover. Bag size is measured by weight, like 60lb or 80lb. But the yield is measured by volume, like cubic feet.
Let’s look at bag size and the space they fill. A bag of concrete is not just sand and cement. It has stone or gravel too. This mix makes it strong. When you add water, the dry stuff mixes. It shrinks down a bit into a wet paste that hardens.
How Much Does a 60lb Concrete Bag Make?
Now let’s focus on the 60 lb concrete bag cubic feet yield. How much wet concrete do you get from one 60lb bag? Most concrete mixes are standard. They use specific amounts of cement, sand, and gravel. A common yield for a 60lb bag is about 0.5 cubic feet. This means one 60lb bag, when mixed with water, will fill a space of 0.5 cubic feet.
Think of our cubic yard box again. It holds 27 cubic feet. A 60lb bag gives you 0.5 cubic feet of concrete. We need to fill 27 cubic feet. How many times does 0.5 cubic feet fit into 27 cubic feet? We can find this out by dividing.
27 cubic feet (in one yard) / 0.5 cubic feet (from one 60lb bag) = 54
Wait, earlier I said about 45 bags. Why is the math 54? Good question! The yield of 0.5 cubic feet per 60lb bag is a common estimate for standard concrete mix. But concrete bags sold for home use can vary slightly. Also, how much water you add changes the final volume a tiny bit. Manufacturers often list the yield on the bag. Many common mixes designed for general use have a slightly higher yield, meaning you need fewer bags than simple division suggests based on a raw 0.5 cubic foot figure.
A more practical and common yield for a 60lb bag used in typical projects is closer to 0.6 cubic feet. Let’s use that number.
27 cubic feet (in one yard) / 0.6 cubic feet (from one 60lb bag, typical yield) = 45
Ah, there we have it! Using the more realistic yield of 0.6 cubic feet per 60lb bag, you get 45 bags per cubic yard. This is the number widely used in the building world for estimating. Always check the bag label for its exact yield, but 45 is a very safe bet for planning.
How Many Bags Per Yard?
So, to fill a space that is one cubic yard of concrete, you will need around 45 bags of the 60lb size. This is the key number of concrete bags per yard for this bag size.
Let’s make this clearer with a simple table:
Table: 60lb Concrete Bag Yield
| Measure | Amount |
|---|---|
| One Cubic Yard | 27 cubic feet |
| One 60lb Bag Yield | About 0.6 cubic feet |
| Bags Needed | 27 / 0.6 = 45 bags |
This table shows the simple math. You need 45 bags. Each bag makes 0.6 cubic feet. 45 bags * 0.6 cubic feet/bag = 27 cubic feet. And 27 cubic feet is one cubic yard.
Other Bag Sizes and Their Yields
Concrete comes in different bag sizes. The 60lb bag is popular. The 80lb bag is also very common. Let’s look at the 80 lb concrete bag yield. An 80lb bag has more dry mix. So, it makes more wet concrete. A common yield for an 80lb bag is about 0.75 cubic feet.
Let’s figure out how many 80lb bags make a cubic yard. The cubic yard is still 27 cubic feet.
27 cubic feet (in one yard) / 0.75 cubic feet (from one 80lb bag) = 36
So, you need about 36 bags of the 80lb size to get one cubic yard. Fewer bags, but each bag is heavier to carry.
Here’s a look at different concrete bag size volume yields:
Table: Common Concrete Bag Yields
| Bag Size (lb) | Common Yield (cubic feet) | Bags per Cubic Yard (27 cu ft) |
|---|---|---|
| 40 | About 0.3 | 27 / 0.3 = 90 |
| 50 | About 0.375 | 27 / 0.375 = 72 |
| 60 | About 0.6 | 27 / 0.6 = 45 |
| 80 | About 0.75 | 27 / 0.75 = 36 |
Note: These yields are common estimates. Always check the bag label for the exact yield.
This table is super helpful for estimating concrete requirements. You can quickly see how many bags of any common size you need for one cubic yard.
Factors That Change How Much Concrete You Get
The yields listed above are good guides. But sometimes the actual amount of concrete you get from a bag can be a little different. Why? A few things play a part:
- How much water you add: Adding too much water makes the concrete weaker. It can also slightly change the volume. Use the amount of water told on the bag.
- How well you mix it: Make sure all the dry mix gets wet and mixed evenly. Dry clumps mean less usable concrete.
- How you place and finish it: Packing the concrete tightly (tamping) removes air pockets. This is good for strength. But it means you fill the space completely, which uses up the volume you calculated. Wasting mix or spilling reduces the final amount in your form.
- The specific mix: Different types of concrete mixes might have slightly different densities. This can affect the yield a tiny bit.
These factors usually don’t change the number of bags per yard by a lot. But they can explain small differences you might see. Always plan to buy a little extra concrete, maybe 10%, just in case. This helps with spills or if your depth was a bit off.
How to Calculate Concrete Bags Needed for Your Project
Knowing how many bags are in a yard is great. But you need to know how many bags you need for your specific job. Most home projects are not exactly one cubic yard. They might be smaller, or maybe a few cubic yards.
Here are the steps to calculate concrete bags needed:
Step 1: Find the Volume of Your Area
First, you need to know the size of the space you want to fill with concrete. You need three measurements:
- Length
- Width
- Depth (or thickness)
Make sure all your measurements use the same units. Feet are easiest if you’re thinking in cubic feet or cubic yards.
Example: You want to pour a small patio.
Length = 10 feet
Width = 8 feet
Depth = 4 inches
Hold on, we used feet for length and width, but inches for depth. We need them all in feet. How many feet is 4 inches? There are 12 inches in a foot. So, 4 inches is 4 divided by 12.
4 inches / 12 inches/foot = 0.333… feet (we can round to 0.34 feet for ease)
Now all measurements are in feet:
Length = 10 feet
Width = 8 feet
Depth = 0.34 feet
Next, multiply these three numbers to get the volume in cubic feet.
Volume = Length * Width * Depth
Volume = 10 feet * 8 feet * 0.34 feet
Volume = 80 * 0.34 cubic feet
Volume = 27.2 cubic feet
Your patio needs 27.2 cubic feet of concrete.
Step 2: Decide on Your Bag Size
You can use 40lb, 50lb, 60lb, or 80lb bags. Let’s say you want to use the 60lb bags because they are a good balance of weight and yield. Remember, a 60lb bag gives about 0.6 cubic feet of concrete.
Step 3: Calculate the Number of Bags
Now divide the total volume you need (in cubic feet) by the yield of one bag (in cubic feet).
Number of Bags = Total Volume Needed / Yield per Bag
Number of Bags = 27.2 cubic feet / 0.6 cubic feet/bag
Number of Bags = 45.33… bags
You can’t buy part of a bag. You always need to round up to the next whole bag.
So, you need 46 bags of 60lb concrete.
Step 4: Add for Waste
It’s wise to add a little extra. Things happen. You might spill some. The ground might be a bit lower in one spot than you thought. Adding 10% is common.
10% of 46 bags = 0.10 * 46 = 4.6 bags
Round this up to 5 bags extra.
Total bags needed = 46 (calculated) + 5 (extra) = 51 bags.
For that 10×8 foot patio, 4 inches deep, using 60lb bags, you should plan to buy about 51 bags.
Estimating Concrete Requirements
Let’s try another example for estimating concrete requirements. Suppose you need a thicker slab for a shed base.
Length = 12 feet
Width = 10 feet
Depth = 6 inches
Convert inches to feet:
6 inches / 12 inches/foot = 0.5 feet
Calculate Volume:
Volume = 12 feet * 10 feet * 0.5 feet
Volume = 120 * 0.5 cubic feet
Volume = 60 cubic feet
Let’s use 80lb bags this time. An 80lb bag yields about 0.75 cubic feet.
Calculate Number of Bags:
Number of Bags = Total Volume Needed / Yield per Bag
Number of Bags = 60 cubic feet / 0.75 cubic feet/bag
Number of Bags = 80 bags
Add 10% for waste:
10% of 80 bags = 0.10 * 80 = 8 bags
Total bags needed = 80 + 8 = 88 bags.
For that 12×10 foot shed base, 6 inches deep, using 80lb bags, you need about 88 bags.
Using a Concrete Volume Calculator
Doing the math by hand is fine. But there are tools to help. An online concrete volume calculator can make this much faster and easier. You just put in the length, width, and depth of your area. The calculator figures out the volume in cubic feet or cubic yards. Then, it asks you what size bag you plan to use (like 60lb or 80lb). It uses the typical yield for that bag size and tells you how many bags you need.
Some calculators even let you add a percentage for waste. Using a calculator helps avoid math mistakes. It’s a good tool for planning your project and creating a shopping list. Just search online for “concrete volume calculator” and you’ll find many free options.
Remember to choose the right shape in the calculator if your area is not a simple rectangle (like a circle or a tube for fence posts).
Why Accurate Calculation Matters
Getting the right number of concrete bags per yard or for your specific project size is important for many reasons:
- Cost: Concrete bags cost money. Buying too many bags wastes money. You might not be able to return opened or wet bags.
- Waste: Extra bags take up space. You have to store them. Dry concrete should be kept dry. If they get wet, they are ruined. Having fewer wasted bags is better for the environment too.
- Running Short: Buying too few bags is a big problem. If you are pouring a slab, you must do it all at once. You can’t stop and go buy more bags later. The concrete starts to set. A “cold joint” forms where the old and new concrete meet. This joint is weak. It can crack. Running short means rushing to the store or maybe ruining your work.
- Effort: Concrete bags are heavy. Carrying, moving, and mixing extra bags you don’t need is extra hard work.
- Project Success: Having the right amount of concrete means you can finish your pour properly. You can take your time to mix it right, place it well, and finish the surface smoothly. This leads to a strong, good-looking finished project.
Taking a little time to calculate concrete bags needed before you start saves time, effort, and money in the long run.
Deciphering Concrete Bag Labels
When you buy concrete bags, look closely at the label. It has important information.
- Type of Concrete: Is it standard mix? Fast-setting? High-strength? Mixes can be different for patios, fence posts, or steps.
- Weight: 60 lb, 80 lb, etc.
- Yield: This is the key number for our calculation. It will say something like “Yields approx. 0.6 cu. ft.” for a 60lb bag, or “Yields approx. 0.75 cu. ft.” for an 80lb bag. Use this number if it is listed.
- Water Needed: It tells you how much water to add per bag. This is important for getting the right strength and workability.
- Mixing Instructions: Steps on how to mix the concrete properly.
- Safety Warnings: Concrete can burn your skin. Wear gloves and eye protection.
Always check the yield on the bag itself. While 0.6 cubic feet for 60lb and 0.75 cubic feet for 80lb are common, checking the label gives you the most accurate number for that specific bag.
Getting Ready to Mix and Pour
Once you have calculated how many bags you need and bought them, you need to get ready to mix and pour.
- Gather Tools: You will need buckets for water, a hoe or shovel for mixing in a wheelbarrow, or a concrete mixer. You’ll also need tools to place and smooth the concrete (like a trowel).
- Prepare the Area: Your area needs to be ready before you mix the first bag. Build your forms (the sides that hold the concrete in place). Make sure the ground inside is level and packed firm. If you are pouring a slab, add gravel and maybe wire mesh or rebar for strength.
- Plan Your Mixing: Mixing concrete is hard work. If you need many bags, plan how you will mix them. You might rent a small mixer. This is much faster than mixing by hand in a wheelbarrow. Mix only as much as you can place and finish in about an hour, especially in warm weather.
- Mix Consistently: Add the correct amount of water to each bag. Too much water makes weak concrete. Mix each bag fully until the concrete is all the same color and texture, like thick oatmeal.
Knowing the concrete bag yield helps you plan the work. If you know a 60lb bag makes 0.6 cubic feet, you can figure out how many bags you can mix in one batch if you have a certain size mixer or wheelbarrow.
Example: Your wheelbarrow holds about 3 cubic feet.
Number of 60lb bags you can mix = Wheelbarrow volume / Yield per bag
Number of bags = 3 cubic feet / 0.6 cubic feet/bag = 5 bags.
So, you can mix 5 bags at a time in that wheelbarrow. This helps you pace yourself.
Fathoming Different Concrete Types
Not all concrete mixes are the same. The standard mix (often called Quikrete 5000 or similar names) is good for general jobs like patios or walkways. But there are other types, which might affect the concrete bag size volume slightly, or more importantly, how they are used and how fast they set.
- Fast-Setting Concrete: Sets up very quickly (in 20-40 minutes). Good for setting fence posts when you want to finish fast. The yield per bag is usually similar to standard mix, but always check.
- High-Strength Concrete: Designed for stronger results. Might have a slightly different mix design, which could affect yield marginally. Used for projects needing extra durability.
- Mortar Mix: Used for laying bricks or blocks. It has no large gravel, just sand and cement. The yield calculations are different because its use is different.
- Concrete Mix with Fiber: Has small fibers added for extra strength and crack resistance. Yield per bag is usually the same as the base mix.
When you are estimating concrete requirements, make sure you choose the right type of concrete for your job. Then use the yield listed on that specific bag for your calculations.
Putting It All Together
Let’s review the main steps for figuring out how much concrete you need and how many 60lb bags that means:
- Measure Your Area: Get the length, width, and depth (thickness) of the space you need to fill. Use the same units for all measurements, like feet. Remember to convert inches to feet (divide inches by 12).
- Calculate Volume: Multiply length * width * depth to get the volume in cubic feet.
- Know the Bag Yield: Find the yield of the 60lb bag you plan to use. A common yield is 0.6 cubic feet per bag. Check the bag label to be sure.
- Divide for Bags: Divide your total volume needed (in cubic feet) by the yield of one 60lb bag (in cubic feet). This gives you the number of bags.
- Round Up: Always round up to the next whole bag.
- Add for Safety: Add an extra 10% or so to your bag count for waste or minor errors.
Example: You need to pour footings for a deck. Each footing hole is a cylinder (like a tube). Let’s say each hole is 2 feet deep and 10 inches across (diameter).
First, calculate the volume of one hole.
Diameter = 10 inches. Radius = half of diameter = 5 inches.
Convert radius and depth to feet:
Radius = 5 inches / 12 inches/foot = 0.417 feet (approx)
Depth = 2 feet
Volume of a cylinder = Pi * Radius² * Depth (Pi is about 3.14)
Volume = 3.14 * (0.417 feet)² * 2 feet
Volume = 3.14 * (0.174 sq ft) * 2 feet
Volume = 3.14 * 0.348 cubic feet
Volume = 1.09 cubic feet (approx) per hole.
Let’s say you have 8 footing holes.
Total volume needed = Volume per hole * Number of holes
Total volume needed = 1.09 cubic feet/hole * 8 holes
Total volume needed = 8.72 cubic feet.
Using 60lb bags (0.6 cubic feet yield):
Number of bags = Total Volume Needed / Yield per Bag
Number of bags = 8.72 cubic feet / 0.6 cubic feet/bag
Number of bags = 14.53 bags
Round up to 15 bags.
Add 10% for waste:
10% of 15 bags = 1.5 bags. Round up to 2 bags extra.
Total bags needed = 15 + 2 = 17 bags.
So, you need about 17 bags of 60lb concrete for these 8 footings.
This detailed process helps you get the right number of bags, whether you are pouring a small slab, fence posts, or other concrete shapes. The key is always figuring out the total volume in cubic feet first, knowing your concrete bag yield, and then dividing.
Using a concrete volume calculator can really simplify these steps, especially for common shapes like slabs or cylinders.
Understanding the relationship between a cubic yard of concrete (27 cubic feet) and the volume each concrete bag size volume provides (like 0.6 cubic feet for a 60lb bag or 0.75 cubic feet for an 80lb bag) is the core of estimating concrete requirements accurately. It all comes back to that simple division once you know the total volume needed for your project.
Remember the number: about 45 bags of 60lb concrete per cubic yard. This is your benchmark. For smaller projects, calculate the volume in cubic feet and divide by the bag yield (0.6 cu ft for 60lb). Always round up and add a little extra. This approach ensures you have enough material to complete your project smoothly and successfully. Happy concreting!
Frequently Asked Questions
How many bags of concrete do I need for a 10×10 slab?
To figure this out, you need the depth of the slab. Let’s say it’s 4 inches thick.
Convert depth to feet: 4 inches / 12 = 0.33 feet.
Calculate volume: 10 ft * 10 ft * 0.33 ft = 33 cubic feet.
A 60lb bag yields about 0.6 cubic feet.
Bags needed: 33 / 0.6 = 55 bags.
Round up: 55 bags.
Add 10% extra: 55 * 0.10 = 5.5 bags. Round up to 6 extra bags.
Total: 55 + 6 = 61 bags.
You need about 61 bags of 60lb concrete for a 10×10 foot slab that is 4 inches thick.
How much does a cubic yard of concrete weigh?
A cubic yard of concrete is heavy! It weighs about 4,000 pounds (2 tons). This is why ready-mix concrete comes in big trucks. For projects needing a cubic yard or more, it’s often easier to order from a ready-mix company than to mix 45+ bags yourself.
Is it cheaper to mix bags or order a truck?
For small jobs, like a few fence posts or a small repair, bags are much cheaper and easier. For bigger jobs, like a patio or driveway that needs several cubic yards, ordering a ready-mix truck is usually cheaper per cubic yard and saves a huge amount of work. There is often a minimum order amount for trucks, though.
Can I mix concrete bags in a wheelbarrow?
Yes, you can mix concrete in a wheelbarrow. This is good for small amounts, like one or two bags at a time. Mix only what you can use quickly. It takes a lot of effort to mix many bags this way. For more bags, a concrete mixer is better.
What is concrete yield?
Concrete yield is the amount of wet, mixed concrete you get from one bag of dry mix. It is usually measured in cubic feet. For a 60lb bag, the yield is often about 0.6 cubic feet. For an 80lb bag, it’s about 0.75 cubic feet. This number helps you know how much space one bag will fill.
Does adding more water give more concrete?
Adding too much water makes concrete weaker. It might seem like it adds volume, but it hurts the final strength. Always use the amount of water listed on the bag instructions for the best result. Using the right water amount helps the concrete harden correctly and reach its planned strength.
How long does concrete take to set?
Concrete starts to get hard (set) quite quickly once water is added. You usually have about 30-60 minutes to mix, place, and finish it. It will be hard enough to walk on in 24-48 hours. It takes about 7 days to reach most of its strength and keeps getting stronger for about 28 days. The exact time depends on the concrete type, temperature, and humidity.