Concrete is ordered from a plant in cubic yards but sold at the hardware store in bags, so most projects need a quick conversion. A cubic yard is 27 cubic feet. An 80 lb bag of concrete mix yields about 0.60 ft³, so one cubic yard takes 45 bags of 80 lb mix. The same yard is 60 bags of 60 lb, 72 bags of 50 lb fast-setting mix, or 90 bags of 40 lb. This calculator converts any volume in cubic yards, cubic feet or cubic metres into bags of each size, adds waste and shows the weight you'll be moving.
If you don't know the volume yet, start with the concrete slab calculator, the concrete column & post hole calculator for round piers, or the cubic yard calculator for any rectangle.
How to use the concrete bags per yard calculator
- Enter the volume and choose its unit: cubic yards, cubic feet or cubic metres.
- Add a waste allowance. 5–10% is typical for slabs; holes and forms with uneven sides may need more.
- Choose the bag size you plan to buy to get a single shopping number. The other sizes are shown underneath for comparison.
- Optionally enter the price per bag. Compare the total with a ready-mix quote once you are above about 1 yard.
Formula
Yields used: 80 lb = 0.60 ft³, 60 lb = 0.45 ft³, 50 lb fast-setting = 0.375 ft³, 40 lb = 0.30 ft³, as published by the manufacturer. Those yields work out to about 133 lb of dry mix per cubic foot of finished concrete.
Worked example
You need 1.5 cubic yards for a patio and add 5% for waste, buying 80 lb bags.
- Volume: 1.5 × 27 = 40.5 ft³; with 5%: 40.5 × 1.05 = 42.53 ft³.
- Bags: 42.53 ÷ 0.60 = 70.9, so 71 bags of 80 lb.
- Weight: 71 × 80 = 5,680 lb of dry mix, nearly three tons.
- The same volume would take 95 × 60 lb bags, 114 × 50 lb bags or 142 × 40 lb bags.
Cubic yards to bags chart
Bags needed for common volumes, no waste added (round up for your waste allowance).
| Cubic yards | ft³ | 80 lb bags | 60 lb bags | 50 lb bags | 40 lb bags |
|---|---|---|---|---|---|
| 0.25 | 6.75 | 12 | 15 | 18 | 23 |
| 0.50 | 13.50 | 23 | 30 | 36 | 45 |
| 0.75 | 20.25 | 34 | 45 | 54 | 68 |
| 1.00 | 27.00 | 45 | 60 | 72 | 90 |
| 1.50 | 40.50 | 68 | 90 | 108 | 135 |
| 2.00 | 54.00 | 90 | 120 | 144 | 180 |
| 2.50 | 67.50 | 113 | 150 | 180 | 225 |
| 3.00 | 81.00 | 135 | 180 | 216 | 270 |
Bags to cubic yards (the reverse)
Already have bags on a pallet? This shows how much concrete they make and how much 4 inch slab they cover.
| Bags of 80 lb | ft³ | Cubic yards | Covers at 4 in thick (ft²) |
|---|---|---|---|
| 10 | 6.0 | 0.22 | 18 |
| 20 | 12.0 | 0.44 | 36 |
| 30 | 18.0 | 0.67 | 54 |
| 45 | 27.0 | 1.00 | 81 |
| 60 | 36.0 | 1.33 | 108 |
| 90 | 54.0 | 2.00 | 162 |
So 45 bags of 80 lb mix make one cubic yard and cover about 81 ft² at 4 inches, roughly a 9 × 9 ft pad.
When a truck beats bags
Three yards of concrete in 80 lb bags is 135 bags and 10,800 lb of mix, more than most pickups can carry in several trips. Ready-mix trucks carry up to about 9 to 10 yd³, and suppliers often deliver smaller loads for a short-load fee. Bags make the most sense for post holes (see the fence post concrete calculator), steps, small pads like a 10x10 slab, and jobs where a truck can't reach the pour.
Caveats and assumptions
- Yields assume the manufacturer's recommended water. They are per bag of standard concrete mix; mortar, sand mix and high-strength products yield differently.
- The 50 lb fast-setting yield is for post-setting mix that is poured dry into the hole and then watered; follow the bag directions.
- Bag counts are rounded up to whole bags. Keep receipts so unopened bags can be returned.
- Concrete in bags is heavy. Check your vehicle payload, and lift with care or have bags delivered.
Frequently asked questions
How many 80 lb bags of concrete make a yard?
45 bags. A cubic yard is 27 ft³ and each 80 lb bag yields about 0.60 ft³, so 27 ÷ 0.60 = 45.
How many 60 lb bags of concrete are in a yard?
60 bags, because each 60 lb bag yields about 0.45 ft³ and 27 ÷ 0.45 = 60.
How many 50 lb bags of fast-setting concrete per yard?
72 bags at 0.375 ft³ each. Fast-setting mix is mainly used for posts, not slabs.
How many 40 lb bags of concrete are in a cubic yard?
90 bags, since each yields about 0.30 ft³.
How many bags of concrete are in a cubic foot?
About 1.7 bags of 80 lb mix (1 ÷ 0.60), 2.2 bags of 60 lb or 3.3 bags of 40 lb.
How much does a yard of bagged concrete weigh?
The dry mix for one yard is 45 × 80 = 3,600 lb. Once water is added and it cures, a yard of concrete weighs roughly 3,900 to 4,050 lb.
Sources
- Quikrete — Concrete Calculator and product yields — yield per 80, 60 and 40 lb bag
- Quikrete — Fast-Setting Concrete Mix — 50 lb fast-setting mix for posts
- National Ready Mixed Concrete Association — ready-mixed concrete ordering and delivery
- NIST — Unit Conversion — cubic yards, cubic feet and cubic metres
This calculator gives estimates for planning and education. Check measurements, local codes, supplier specs and your school's official policy before relying on a result. See our disclaimer and how we build and check calculators.