Slabs / blocks / bags
Concrete Weight Calculator
A 10 by 10 ft slab 4 in thick holds 33.33 cu ft (1.23 cu yd), about 4,667 lb of concrete at 140 lb per cubic foot.
Sources checked
Your estimate
4,667 lb of concrete
33.33 cu ft, 1.23 cu yd, 2.33 short tons.
- Cubic yards1.23
- Short tons2.33
How much a slab, block or bag weighs
- Find the volume. For a slab: length x width x thickness in inches / 12. For 10 ft by 10 ft and 4 in: 10 x 10 x 4 / 12 = 33.33 cu ft. A solid block is length x width x height in feet.
- Multiply by the weight of a cubic foot. The 1101 sheet prints about 140 lb: 33.33 x 140 = 4,667 lb, which is 2.33 short tons.
- For bags, the label is the dry weight. The cubic feet a bag makes are on how many cubic feet a bag makes; the mixed batch weighs more than the dry bag because water goes in.
Numbers we use
- One cubic foot of mixed concrete
- 140 lbQUIKRETE Concrete Mix 1101 data sheet (Oct 2022)
- One cubic yard, 27 cu ft
- 3,780 lbQUIKRETE Concrete Mix 1101 data sheet (Oct 2022)
A 10 by 10 ft slab at three thicknesses
| Thickness | Cu ft | Cu yd | Pounds | Short tons |
|---|---|---|---|---|
| 4 in | 33.33 | 1.23 | 4,667 | 2.33 |
| 5 in | 41.67 | 1.54 | 5,833 | 2.92 |
| 6 in | 50 | 1.85 | 7,000 | 3.5 |
Sources: QUIKRETE Concrete Mix 1101 data sheet (Oct 2022)
Where sources agree on the mix
Weight of a cubic foot of mixed concrete
- about 140 lbQUIKRETE Concrete Mix 1101 data sheet (Oct 2022)
- about 140 lbQUIKRETE 5000 Concrete Mix 1007 data sheet (Nov 2022)
140 lb, from the 1101 sheet, which the bag yields on the other pages also come from. The two sheets print the same figure, and neither splits wet from cured.
Concrete weight questions
How much does a cubic yard of concrete weigh?
About 3,780 lb, or 1.89 short tons: 27 cubic feet at 140 lb each, by QUIKRETE's 1101 sheet.
How much does a cubic foot of concrete weigh?
About 140 lb. QUIKRETE's 5000 sheet prints the same 140 lb, so the two agree.
How much does a 4 inch concrete slab weigh per square foot?
46.7 lb per square foot: a 4 in layer is a third of a foot, at 140 lb a cubic foot.
How much does a 10 by 10 foot concrete slab weigh?
4,667 lb at 4 in thick, 5,833 lb at 5 in and 7,000 lb at 6 in (33.33, 41.67 and 50 cu ft). Volume and bags for the same slab are on the concrete slab calculator.
How much does a bag of concrete weigh?
The label is the dry weight: 40, 50, 60 or 80 lb. A 60 lb bag makes 0.45 cu ft once mixed, about 63 lb of concrete, and the water added makes up the difference. A stack of bags is on the concrete bags calculator and the pallet on the bags per pallet page.
How much does a concrete block weigh?
A hollow 8x8x16 block weighs 40 lb, as Basalite prints it. This page counts solid concrete, so a solid block of the same size weighs far more; the wall figures are on the concrete block calculator.
Does concrete get lighter as it cures?
Our source gives one figure for the mix, about 140 lb per cubic foot, and does not split wet from cured. The page uses that one number for both.
A planning aid, not an engineering calculation: your local code and building inspector have the final word. Terms