Concrete
Work out how much concrete a pour needs, in the unit you are going to order it in. The bag yields below are the ones these calculators use.
- Concrete Calculator
Enter the dimensions of the pour to get the volume in cubic yards, the number of bags by size, and how much ready-mix to order.
Bag yields and bags per cubic yard
| Bag | Yield | Bags per cubic yard |
|---|---|---|
| 40 lb | 0.30 cu ft | 90 |
| 50 lb | 0.375 cu ft | 72 |
| 60 lb | 0.45 cu ft | 60 |
| 80 lb | 0.60 cu ft | 45 |
| 90 lb | 0.675 cu ft | 40 |
Yields are published "approximately" and are specific to this product. Bags per cubic yard is derived — 27 divided by the yield — and is not a published figure. Sand and topping mixes yield around ten percent more per pound, so check the bag you are actually buying.
Source: QUIKRETE Concrete Mix No. 1101 — technical data sheet — read 2026-09-09
Bags or ready-mix
The threshold most people are actually looking for is around one and a half to two cubic yards. Below it, bags are usually the better answer — that is roughly 68 to 90 bags at 80 pounds, which is a long day for two people but does not involve a truck or a delivery window. Above it, order ready-mix.
Ready-mix plants sell in quarter-yard increments with a minimum, and charge a short-load fee below three or four yards. The fee is per delivery and does not scale with how far under you are, so a 2.5-yard order and a 3.5-yard order can land on the same ticket.
Shared assumptions
Every calculator in this section applies the waste allowance to the volume, once, before any rounding to bags or to the ordering increment. Rounding twice would inflate the answer, and the bag count is already a ceiling.
The unit weight used for mass is the one on the data sheet above — approximately 140 pounds per cubic foot. Mass is shown to two significant figures because the source states it approximately, and carrying more digits than the source supports is false precision a professional spots immediately.