Concrete for a 10 × 10 Slab by Thickness
Cubic yards and bag counts for a 100 sq ft slab at every thickness from 2 to 12 inches, including a 10% waste allowance. Volume scales straight with thickness, so 6 in costs exactly half again what 4 in does.
Source data and formula checked · How we check
Concrete for a 10 × 10 Slab by Thickness reads concrete needed straight off thickness, for 11 values from 2 to 12. Every row is computed from the same formula the calculator uses, not measured or copied from another table, so a value between two rows can be worked out the same way. The formula is the one published by American Concrete Institute.
Past about 1 cubic yard — roughly 5 in on this slab — ready-mix delivery beats mixing bags on both cost and time.
| Thickness (inch) | Concrete needed | 60 lb bags (0.45 cu ft each) | 80 lb bags (0.60 cu ft each) |
|---|---|---|---|
| 2 | 0.68 cu yd | 41 bags | 31 bags |
| 3 | 1.02 cu yd | 62 bags | 46 bags |
| 4 | 1.36 cu yd | 82 bags | 62 bags |
| 5 | 1.70 cu yd | 102 bags | 77 bags |
| 6 | 2.04 cu yd | 123 bags | 92 bags |
| 7 | 2.38 cu yd | 143 bags | 107 bags |
| 8 | 2.72 cu yd | 163 bags | 123 bags |
| 9 | 3.06 cu yd | 184 bags | 138 bags |
| 10 | 3.40 cu yd | 204 bags | 153 bags |
| 11 | 3.73 cu yd | 225 bags | 169 bags |
| 12 | 4.07 cu yd | 245 bags | 184 bags |
Questions people actually ask
- How do I read the Concrete for a 10 × 10 Slab by Thickness chart?
- Find your thickness in the first column and read across. At 2 inch the concrete needed is 0.68 cu yd; at 12 inch it is 4.07 cu yd. The table runs from 2 inch to 12 inch in 11 rows.
- How much does the concrete needed change per row?
- By 0.34 cu yd for every 1 inch of thickness, and by the same amount everywhere in the table — the relationship is a straight line, so halfway between two rows is halfway between their two answers. That is what makes reading between the rows safe here.
- What if my thickness is outside the table?
- The chart covers 2 inch to 12 inch, which is the range people actually look up. Anything above or below goes into the calculator, which takes any figure and shows each step of the working rather than only the result. Open the concrete calculator.
- Where do these numbers come from?
- Every row is computed at build time from the formula published by American Concrete Institute, by the same code behind the calculator — not transcribed from another table, which is how a rounding error in one chart ends up in twenty.
Need a different number?
The chart covers the common values. For anything between the rows, the concrete calculator takes any figure and shows the working.
Source: American Concrete Institute, Portland Cement Association