How many 60 pound bags of concrete make a yard? About 45 of the 60 lb bags of concrete make one cubic yard. A 60 lb bag usually gives about 0.022 cubic yards or about 0.6 cubic feet of concrete after mixing. If you use 80 lb bags instead, you need about 34 of those bags to make a cubic yard. This guide helps you figure out exactly what you need for your project.
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Figuring Out Concrete Volume
Concrete is measured by volume. Think of it like space. The most common unit for large amounts of concrete is the cubic yard.
Grasping Cubic Yards
A cubic yard is a cube shape. Each side of the cube is 3 feet long.
- Length: 3 feet
- Width: 3 feet
- Height: 3 feet
To find the volume of this cube, you multiply the length, width, and height:
3 feet * 3 feet * 3 feet = 27 cubic feet.
So, one cubic yard is always 27 cubic feet. This number is important for figuring out how much concrete you need.
Concrete Bags and What They Hold
Concrete for small jobs often comes in bags. These bags hold a dry mix. You add water to this mix to make wet concrete.
The bags are sold by weight. Common sizes are 60 pounds and 80 pounds. But the weight of the dry mix is not the same as the volume of the wet concrete you get.
Finding Out Concrete Bag Yield
The amount of wet concrete you get from one bag is called the concrete bag yield. This yield is measured in volume, like cubic feet or cubic yards.
Bag makers design the mix so a certain weight gives a fairly standard amount of wet concrete. But this can change a little bit. Adding too much water or too little water can affect the final volume slightly. Also, different brands might have slightly different mixes.
How Much Concrete in a 60 lb Bag?
A 60 lb bag of concrete is made to produce a specific volume of wet concrete when mixed right.
Typically, a 60 lb concrete bag gives you about 0.6 cubic feet of mixed concrete.
- How much concrete in 60 lb bag: Around 0.6 cubic feet.
- 60 lb concrete bag cubic feet: About 0.6 cubic feet.
To put this in cubic yards, remember 1 cubic yard is 27 cubic feet.
0.6 cubic feet / 27 cubic feet per yard = about 0.022 cubic yards.
So, one 60 lb bag gives you a very small fraction of a cubic yard.
Calculating Bags for a Yard
Now we can figure out how many of these 60 lb bags make a whole cubic yard.
We know:
* 1 cubic yard = 27 cubic feet
* 1 bag (60 lb) = about 0.6 cubic feet
To find the number of bags, divide the total volume needed (1 cubic yard or 27 cubic feet) by the volume one bag makes (0.6 cubic feet).
Number of bags = Total Volume Needed / Volume Per Bag
Number of bags = 27 cubic feet / 0.6 cubic feet per bag
27 / 0.6 = 45
So, you need about 45 of the 60 lb bags of concrete to make one cubic yard.
This is the standard number most people use for planning.
Factors That Change The Number
The number 45 is a good estimate. But the real number might be a little more or a little less. Why?
- How You Mix It: Adding the correct amount of water is key. Too much water can lower the strength and might change the volume slightly.
- Specific Mix Design: Different concrete mixes (like high-strength or fast-setting) might have slightly different yields per bag. Always check the bag label.
- Waste: You might spill some mix, leave some in the wheelbarrow, or have a little extra at the end you don’t use. This waste means you need more bags than the pure math suggests.
- Compaction: How well you spread and smooth the concrete can affect how much volume it takes up in the space.
Because of these things, it’s smart to always get a little extra concrete. Buying one or two extra bags (about 5-10% more than you calculate) is a good idea. It saves you a trip to the store if you run short.
Comparing 60 lb Bags to 80 lb Bags
Concrete also comes in 80 lb bags. These bags have more dry mix. So, they make more wet concrete.
An 80 lb bag typically yields about 0.75 cubic feet of mixed concrete.
- 80 lb concrete bag volume: About 0.75 cubic feet.
How many 80 lb concrete bags make a yard? Let’s do the math again:
Number of bags = Total Volume Needed / Volume Per Bag
Number of bags = 27 cubic feet / 0.75 cubic feet per bag
27 / 0.75 = 36
So, you need about 36 of the 80 lb bags to make one cubic yard. Some sources might say 34 bags, others 36. It depends on the exact mix yield, which can vary slightly. Using 34-36 bags per yard is a good range for planning with 80 lb bags.
Using 80 lb bags means you handle fewer bags for the same amount of concrete. But they are heavier to lift and carry.
Calculating Concrete Needed For Project
Before you buy bags, you need to know the total volume of concrete your project needs. This is a very important step.
Steps to Figure Out Volume
- Measure Your Area: Get the length, width, and depth of the area where the concrete will go.
- Measure in feet and inches.
- Convert all measurements to feet. (Example: 6 inches = 0.5 feet; 3 inches = 0.25 feet).
- Calculate Volume in Cubic Feet: Multiply your measurements:
Volume (cubic feet) = Length (feet) * Width (feet) * Depth (feet) - Convert to Cubic Yards: Divide the total cubic feet by 27 (because 1 cubic yard = 27 cubic feet).
Volume (cubic yards) = Volume (cubic feet) / 27
Example Calculation
Let’s say you want to pour a concrete slab for a small patio.
* Length: 10 feet
* Width: 8 feet
* Depth: 4 inches
Step 1: Convert depth to feet.
4 inches / 12 inches per foot = 0.333 feet (approx.)
Step 2: Calculate volume in cubic feet.
Volume = 10 feet * 8 feet * 0.333 feet
Volume = 80 * 0.333
Volume = 26.64 cubic feet
Step 3: Convert to cubic yards.
Volume = 26.64 cubic feet / 27 cubic feet per yard
Volume = 0.987 cubic yards (approx.)
So, your project needs just under 1 cubic yard of concrete.
Using a Concrete Volume Calculator
Doing the math yourself is good, but there are tools to help. Many websites have a concrete volume calculator.
- You just type in your measurements (length, width, depth).
- The calculator tells you the volume in cubic feet and cubic yards.
- Some calculators even tell you how many bags (60 lb or 80 lb) you might need.
Using a concrete volume calculator can make this step faster and help avoid math mistakes.
Converting Volume to Bags
Once you have the total volume needed in cubic yards, you can figure out the number of bags.
- For 60 lb bags: Multiply the cubic yards needed by 45.
Number of 60 lb bags = Cubic Yards * 45 - For 80 lb bags: Multiply the cubic yards needed by 34 to 36 (using 36 is a safe bet).
Number of 80 lb bags = Cubic Yards * 36
Using our patio example (0.987 cubic yards):
- Number of 60 lb bags = 0.987 * 45 = 44.4 bags
- Number of 80 lb bags = 0.987 * 36 = 35.5 bags
Since you can’t buy parts of bags, you always round up to the next whole number.
- For the patio: 45 bags (60 lb) or 36 bags (80 lb).
Then, add your waste factor (5-10%).
- For 45 bags (60 lb), add 10% waste (4.5 bags). Total: 45 + 5 = 50 bags.
- For 36 bags (80 lb), add 10% waste (3.6 bags). Total: 36 + 4 = 40 bags.
So, for this patio, you would plan to buy about 50 of the 60 lb bags or about 40 of the 80 lb bags.
This step-by-step process helps you calculate concrete needed for project accurately.
Deciphering Concrete Coverage
Sometimes it’s easier to think about how much area a certain amount of concrete covers at a specific thickness. This is the cubic yard concrete coverage.
We know:
* 1 cubic yard = 27 cubic feet.
If you are pouring a slab 1 foot thick, 1 cubic yard covers 27 square feet (1 ft * 27 sq ft = 27 cubic feet).
If you are pouring a slab 6 inches (0.5 feet) thick, 1 cubic yard covers 54 square feet (0.5 ft * 54 sq ft = 27 cubic feet).
If you are pouring a slab 4 inches (0.333 feet) thick, 1 cubic yard covers about 81 square feet (0.333 ft * 81 sq ft = 27 cubic feet).
If you are pouring a slab 2 inches (0.167 feet) thick, 1 cubic yard covers about 162 square feet (0.167 ft * 162 sq ft = 27 cubic feet).
Coverage Per Bag
We can also figure out the coverage for just one bag.
A 60 lb bag yields about 0.6 cubic feet.
To find coverage, divide the bag yield (in cubic feet) by the depth (in feet).
-
Coverage of one 60 lb bag at 4 inches (0.333 ft) deep:
0.6 cubic feet / 0.333 feet = about 1.8 square feet. -
Coverage of one 80 lb bag at 4 inches (0.333 ft) deep: (80 lb bag yields about 0.75 cubic feet)
0.75 cubic feet / 0.333 feet = about 2.25 square feet.
This means for a 4-inch thick slab:
* One 60 lb bag covers about 1.8 square feet.
* One 80 lb bag covers about 2.25 square feet.
Knowing this helps if you are trying to figure out how many bags you need based on the area (square footage) of your project instead of figuring out the cubic volume first.
To use this:
1. Measure the total area of your project in square feet.
2. Figure out the depth of the concrete in feet.
3. Divide the total area by the coverage per bag at that depth.
Example: You need to pour 100 square feet at 4 inches thick.
Using 60 lb bags (1.8 sq ft coverage per bag at 4 inches):
Number of bags = 100 sq ft / 1.8 sq ft per bag = 55.5 bags. Round up to 56 bags. Add waste (e.g., 6 bags for 10%). Total: 62 bags.
Using 80 lb bags (2.25 sq ft coverage per bag at 4 inches):
Number of bags = 100 sq ft / 2.25 sq ft per bag = 44.4 bags. Round up to 45 bags. Add waste (e.g., 5 bags for 10%). Total: 50 bags.
This coverage method is another way to calculate concrete needed for project.
Converting Concrete Bags to Yards
What if you bought a bunch of bags for a project and want to know the total volume you have? You can convert concrete bags to yards.
-
For 60 lb bags: Multiply the number of bags by the yield per bag in cubic yards (about 0.022).
Total Cubic Yards = Number of 60 lb bags * 0.022 cubic yards/bag -
For 80 lb bags: Multiply the number of bags by the yield per bag in cubic yards (about 0.028 – 0.03). Let’s use 0.028 for 0.75 cubic feet (0.75/27).
Total Cubic Yards = Number of 80 lb bags * 0.028 cubic yards/bag
Example: You have 20 bags of 60 lb concrete.
Total Cubic Yards = 20 * 0.022 = 0.44 cubic yards.
Example: You have 15 bags of 80 lb concrete.
Total Cubic Yards = 15 * 0.028 = 0.42 cubic yards.
This helps you see how much volume your bags represent compared to a full cubic yard delivered by a truck.
Getting a Handle on Concrete Yard Weight
A cubic yard of concrete is heavy. Very heavy.
The concrete yard weight depends on the type of concrete mix. Standard concrete weighs roughly 145 pounds per cubic foot.
Since 1 cubic yard is 27 cubic feet:
Concrete Yard Weight = 145 pounds/cubic foot * 27 cubic feet
145 * 27 = 3915 pounds.
So, one cubic yard of concrete weighs nearly 4000 pounds, or about 2 tons.
This is why small projects use bags. Moving a full cubic yard requires heavy machinery or many strong people. Bagged concrete breaks this large weight into smaller, manageable portions (60 lb or 80 lb bags).
Think about the 45 bags of 60 lb concrete needed for a yard.
45 bags * 60 pounds/bag = 2700 pounds (This is the dry weight).
When you add water, the total weight of the mixed concrete is much closer to the ~3900 pounds of a wet cubic yard.
Think about the 36 bags of 80 lb concrete needed for a yard.
36 bags * 80 pounds/bag = 2880 pounds (This is the dry weight).
Again, add water, and the wet weight is around 3900 pounds.
The bag weight is just the dry mix. The final wet concrete weight per yard is higher due to the added water.
Why Knowing Bag Count Matters
Knowing how many bags make a yard is important for several reasons:
- Buying Right: You avoid buying too many bags (wasting money and having extra bags to store or get rid of) or too few (stopping work to go buy more bags).
- Planning Work: You know how many bags you’ll need to mix, move, and place. This helps plan your time and who will help.
- Cost Estimating: You can figure out the total cost of the concrete for your project based on the price per bag.
- Comparing Options: You can compare the cost and effort of using bags versus ordering a concrete truck delivery (which is usually for larger volumes, often 1 cubic yard or more).
Putting It All Together: Project Examples
Let’s look at a few simple project examples.
Example 1: Small Post Footings
You need to set 6 fence posts. Each hole is 8 inches across (diameter) and 3 feet deep.
-
Find volume per footing:
- Radius = Diameter / 2 = 8 inches / 2 = 4 inches.
- Convert radius to feet: 4 inches / 12 inches per foot = 0.333 feet.
- Convert depth to feet: 3 feet.
- Volume of a cylinder = π * radius² * depth (π is about 3.14).
- Volume = 3.14 * (0.333 feet)² * 3 feet
- Volume = 3.14 * 0.111 sq ft * 3 feet
- Volume = 1.045 cubic feet (per footing)
-
Total volume for 6 footings:
- Total Volume = 1.045 cubic feet/footing * 6 footings
- Total Volume = 6.27 cubic feet
-
Convert to cubic yards:
- Total Volume = 6.27 cubic feet / 27 cubic feet per yard
- Total Volume = 0.232 cubic yards
-
Calculate bags needed (using 60 lb bags):
- Number of bags = 0.232 cubic yards * 45 bags/yard
- Number of bags = 10.44 bags. Round up to 11 bags.
-
Add waste: Add about 10% waste (1.1 bags). Round up to 2 bags waste.
- Total bags: 11 + 2 = 13 bags.
You would plan to buy 13 bags of 60 lb concrete for this project.
Example 2: Pouring a Thin Slab
You want to pour a 2-inch thick concrete slab for a small equipment pad, 5 feet by 5 feet.
-
Find volume:
- Length: 5 feet
- Width: 5 feet
- Depth: 2 inches = 2 inches / 12 inches per foot = 0.167 feet.
- Volume = 5 feet * 5 feet * 0.167 feet
- Volume = 25 * 0.167
- Volume = 4.175 cubic feet
-
Convert to cubic yards:
- Total Volume = 4.175 cubic feet / 27 cubic feet per yard
- Total Volume = 0.155 cubic yards
-
Calculate bags needed (using 80 lb bags):
- Number of bags = 0.155 cubic yards * 36 bags/yard
- Number of bags = 5.58 bags. Round up to 6 bags.
-
Add waste: Add about 10% waste (0.6 bags). Round up to 1 bag waste.
- Total bags: 6 + 1 = 7 bags.
You would plan to buy 7 bags of 80 lb concrete for this small slab.
Accounting for Waste
We mentioned waste a few times. It’s really important for bagged concrete.
Why waste happens:
* Spills while mixing or moving.
* Bags that get wet or hard before you use them.
* Slight over-excavation of your area.
* Not being able to get every last bit out of the mixing container.
A common rule is to add 5% to 10% extra bags to your calculated number.
* For small jobs (just a few bags), maybe round up to the nearest whole bag plus one extra.
* For larger jobs (20+ bags), calculate 10% and round up.
Example: If you calculate 23 bags needed, 10% waste is 2.3 bags. Add 3 extra bags. Total: 26 bags.
It’s much better to have one extra bag at the end than to need just a little bit more concrete and have to stop everything to go buy one bag.
Tips for Bagged Concrete
- Storage: Store bags in a dry place. Moisture makes the concrete hard inside the bag.
- Mixing: Follow the water amount on the bag. Use a clean container. Mix thoroughly.
- Timing: Only mix as much concrete as you can use in about 30-60 minutes. Mixed concrete starts to harden.
- Safety: Wear gloves, eye protection, and a dust mask when working with dry concrete mix. Wet concrete can burn skin.
Quick Reference Table
Here is a simple table to help you remember the key numbers.
| Item | Volume/Quantity | Notes |
|---|---|---|
| 1 Cubic Yard | 27 cubic feet | Standard large volume unit |
| 60 lb Concrete Bag | ~0.6 cubic feet | Yield after mixing |
| ~0.022 cubic yards | Yield in cubic yards | |
| 80 lb Concrete Bag | ~0.75 cubic feet | Yield after mixing |
| ~0.028 cubic yards | Yield in cubic yards | |
| Bags per Cubic Yard | ~45 bags (60 lb) | Estimate |
| ~34-36 bags (80 lb) | Estimate (use 36 for safety) | |
| Coverage (60 lb bag) | ~1.8 sq ft at 4″ deep | Varies with depth |
| Coverage (80 lb bag) | ~2.25 sq ft at 4″ deep | Varies with depth |
| Concrete Yard Weight | ~3900 lbs | Weight of wet concrete |
This table shows the most important facts about concrete bag yield, how much concrete in 60 lb bag, how many 80 lb concrete bags make a yard, and cubic yard concrete coverage.
Frequently Asked Questions (FAQ)
How long can I store concrete bags?
If kept dry and off the ground, concrete bags can last several months. Some say up to a year. But it’s best to use them within a few months for best results. Old bags might have hard lumps inside.
Can I mix concrete in a wheelbarrow?
Yes, for small amounts, a wheelbarrow works fine. For more than a few bags, a concrete mixer is much easier and gives a better mix.
How much water should I add?
The bag will give you a range of water to add. Start with the lower amount. Add more water slowly until the mix is workable but not too wet. Too much water makes the concrete weaker.
What happens if the concrete gets wet before I use it?
If the dry mix in the bag gets wet, it will start to harden. You cannot use concrete that has already started to set in the bag. Store bags in a completely dry place.
Is there a difference between concrete mix and cement mix?
Yes. Cement is just one part of concrete. Concrete mix contains cement, sand, and gravel. When you add water to concrete mix, you get concrete. Cement mix (like Portland cement) is just cement and needs sand and gravel added to make concrete. Bagged concrete sold for general use is usually concrete mix.
In Conclusion
Figuring out how many bags of concrete you need is simple once you know the basic numbers. A cubic yard is 27 cubic feet. A 60 lb bag gives about 0.6 cubic feet, meaning you need about 45 bags per yard. An 80 lb bag gives about 0.75 cubic feet, needing about 36 bags per yard.
Measure your project space, calculate the total cubic feet, divide by 27 to get cubic yards, and then multiply by the number of bags per yard (45 for 60 lb, 36 for 80 lb). Always add a little extra for waste. Use a concrete volume calculator if you want a quick check. Knowing these steps will help you plan your project and buy the right amount of concrete.