Bags of Concrete Calculator
Enter the length, width and depth of your pour to get the number of 40, 60 and 80 lb bags you need, what they cost, and how that compares with ready-mix.
Enter sizes greater than zero.
Prices are US national ranges from published sources, checked September 23, 2026. Where the numbers come from.
Bags per cubic yard
Each bag makes a fixed volume of concrete once mixed. Divide the volume you need, in cubic feet, by the bag's yield and round up.[1]
| Bag | Yield | Bags per cubic yard |
|---|---|---|
| 80 lb | 0.6 cu ft | 45 |
| 60 lb | 0.45 cu ft | 60 |
| 40 lb | 0.3 cu ft | 90 |
Bags for common jobs
Before waste; add about 10%.
| Job | Volume | 80 lb | 60 lb | 40 lb |
|---|---|---|---|---|
| One fence post hole, 10 in wide × 36 in deep | 1.64 cu ft | 3 | 4 | 6 |
| Four deck footings, 12 in × 42 in | 11.00 cu ft | 19 | 25 | 37 |
| 4 × 4 ft pad, 4 in thick | 5.33 cu ft | 9 | 12 | 18 |
| 3 × 10 ft walkway, 4 in thick | 10.00 cu ft | 17 | 23 | 34 |
| 10 × 10 ft slab, 4 in thick | 33.33 cu ft | 56 | 75 | 112 |
Bags or ready-mix?
At $5.93–$6.47 a bag[2], one cubic yard in 80 lb bags (45 bags) costs about $265–$290. Concrete Network puts ready-mix at $160–$195 per cubic yard[4]. Small orders cost more: Fixr reports a short-load charge of $15–$17 per cubic yard under 10 yards[5], and suppliers set their own minimums.
Bags also mean labor: 45 bags of 80 lb is 1.8 tons to lift, mix and place. For anything over a yard or so, price a ready-mix delivery before you buy bags. See ready-mix delivery.
Frequently asked questions
How many 80 lb bags of concrete make a yard?
45. An 80 lb bag yields about 0.6 cubic feet, and a cubic yard is 27 cubic feet.
How many 60 lb bags of concrete make a yard?
60, at about 0.45 cubic feet per bag.
How many 40 lb bags of concrete make a yard?
90, at about 0.3 cubic feet per bag.
How many bags of concrete for a fence post?
A 10 in wide, 36 in deep hole holds about 1.64 cubic feet: 3 bags of 80 lb or 4 of 60 lb, a little less once the post is in. Use the footing and post hole calculator for other sizes.
How much does an 80 lb bag of concrete cost?
The Home Depot listed standard 80 lb Quikrete and Sakrete concrete mix at $5.93–$6.47 a bag when we checked, with the lower price for 42 bags or more. Prices vary by store. See bagged concrete prices.
Sources
- Quikrete, Concrete Mix No. 1101 data sheet, updated 2022-10. Checked September 23, 2026.
- The Home Depot, Quikrete 80 lb Concrete Mix. Figure as shown in the page's search listing; checked September 23, 2026.
- The Home Depot, Sakrete 80 lb Gray Concrete Mix. Figure as shown in the page's search listing; checked September 23, 2026.
- Concrete Network, Concrete prices, updated 2026-07-14. Checked September 23, 2026.
- Fixr, Concrete delivery cost, updated 2025-01-31. Checked September 23, 2026.