Printable Concrete Mix and Bag Yield Chart
Mix ratios, bag yields and slab coverage on one page, so an order can be checked before you drive to the yard.
How to use: Figures assume a level sub-base. Add 5 to 10 percent for uneven ground, and never exceed the water quantity printed on the bag.
Volume, not weight
Concrete is specified by volume and sold by weight, and the yield of a bag depends on the mix. An 80 lb bag yields about 0.6 cubic feet, so a cubic yard takes roughly 45 bags.
Order for the ground you have
A slab that is 4 inches deep in the middle can be 5 inches at the edges. Add 5 to 10 percent, and round up to whole bags, because a pour cannot be paused to fetch more.
Water weakens concrete
Every extra litre of water beyond the mix design lowers strength. If the mix is stiff, add water in small amounts and mix thoroughly rather than pouring it in.
Mix ratios
| Mix (cement:sand:aggregate) | Typical strength | Use |
|---|---|---|
| 1 : 3 : 6 | ~2,000 psi / C15 | Mass fill, footings |
| 1 : 2.5 : 5 | ~2,500 psi | Light-duty slabs |
| 1 : 2 : 4 | ~3,000 psi / C20 | Driveways, paths |
| 1 : 1.5 : 3 | ~3,500 psi / C25 | Structural slabs |
| 1 : 1 : 2 | ~4,000 psi / C30 | High-strength, columns |
Bag yields
| Bag size | Yield (cubic feet) | Yield (cubic metres) | Bags per cubic yard |
|---|---|---|---|
| 40 lb | 0.30 | 0.0085 | 90 |
| 50 lb | 0.375 | 0.0106 | 72 |
| 60 lb | 0.45 | 0.0127 | 60 |
| 80 lb | 0.60 | 0.0170 | 45 |
Slab coverage
| Slab thickness | Sq ft per cubic yard | 80 lb bags per 100 sq ft |
|---|---|---|
| 3 in | 108 | 42 |
| 4 in | 81 | 56 |
| 5 in | 65 | 69 |
| 6 in | 54 | 83 |