Reference · Concrete quantities
A cubic yard of concrete is 27 cubic feet. It takes 45 eighty-pound bags to fill it — or 60 sixty-pound, 72 fifty-pound, or 90 forty-pound bags. Here is the full table, and the point where bags stop making sense.
| Bag size | Yield per bag | Bags per cubic yard | Bags per cubic foot |
|---|---|---|---|
| 80 lb | 0.600 ft³ | 45 | 1.67 |
| 60 lb | 0.450 ft³ | 60 | 2.22 |
| 50 lb | 0.375 ft³ | 72 | 2.67 |
| 40 lb | 0.300 ft³ | 90 | 3.33 |
Yields are the standard manufacturer figures for pre-mixed concrete (Quikrete/Sakrete): an 80 lb bag makes about 0.60 ft³. Actual yield varies slightly with how much water you add.
Once you know a footing’s volume in cubic feet, the bag count is just volume ÷ yield. This is where the “order ready-mix” line shows itself:
| Concrete volume | Cubic yards | 80 lb bags | 60 lb bags |
|---|---|---|---|
| 1 ft³ | 0.04 | 2 | 3 |
| 2 ft³ | 0.07 | 4 | 5 |
| 5 ft³ | 0.19 | 9 | 12 |
| 10 ft³ | 0.37 | 17 | 23 |
| 13.5 ft³ | 0.50 | 23 | 30 |
| 27 ft³ | 1.00 | 45 | 60 |
Mixing 45 bags by hand to make one cubic yard is a full day and a sore back; a truck brings the same yard in minutes. The practical crossover is about one cubic yard: below it, bags are convenient and avoid a truck’s minimum-load fee; above it, ready-mix is cheaper and faster. A typical 250–350 linear foot house footing is 8–12 cubic yards — never a bag job.
Get the exact bag count for your footing from its dimensions on the concrete footing calculator, size a single pad on the pad calculator, or count deck-pier bags on the sonotube size chart.
FootingTakeoff reads a footing plan and returns total linear feet, pad count, and an invoice at your rates — automatically.
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