Formula
Tons are the volume in cubic feet times 145, divided by 2,000. Equivalently, cubic yards times 1.9575. Depth is the finished thickness after compaction. Waste is the only extra factor.
ft³ = shape × depth in feet
tons = ft³ × 145 / 2,000 × (1 + waste ÷ 100)
ton/yd³ = 145 × 27 / 2,000 = 1.9575
145 lb/ft³ is the density specified for this calculator. It was not copied from a state DOT specification in this pass. A figure of about 110 lb per square yard per inch of thickness is roughly 147 pcf, close to 145 and not the same number. Use the plant ticket when you have it. The cubic yard calculator will hand you the volume if the shape is irregular.
Worked examples
10 × 50 ft × 3 in, no waste. 125 ft³. 125 × 145 / 2,000 = 9.06 tons. 4.63 cubic yards.
The same drive with 5% spare. 9.06 × 1.05 = 9.52 tons.
A 4 ft circle, 6 in deep. π × 4 × 0.5 = 6.28 ft³, 0.46 tons before waste.
Reference
Compacted tons at 145 lb/ft³, rectangular, no waste.
| Area | 2 in | 3 in | 4 in |
|---|---|---|---|
| 10 × 20 ft | 2.42 t | 3.63 t | 4.83 t |
| 10 × 50 ft | 6.04 t | 9.06 t | 12.08 t |
| 12 × 40 ft | 5.80 t | 8.70 t | 11.60 t |
Questions
How many tons is a 10 by 50 foot drive at 3 inches?
9.06 tons at 145 lb/ft³, with no waste. 10 × 50 × 3/12 = 125 cubic feet. 125 × 145 / 2,000 = 9.0625 tons.
Is 145 pounds per cubic foot the right density?
It is the compacted density this page uses, and the depth is the finished thickness. A rule of thumb near 110 lb per square yard per inch is about 147 lb/ft³. Your plant’s mix ticket can differ. Add a waste percent if you want spare mix. This page does not add a second compaction factor on top of 145.
What shapes does it take?
A rectangle, a circle from the diameter, and a triangle from base and height. For a driveway that is none of those, break it into pieces or use the cubic yard calculator’s known-area shape and multiply the yards by 1.9575 ton.
Sources
- Compacted hot-mix density used here: 145 lb/ft³. Tons = cubic feet × 145 / 2,000. Depth is finished thickness.
- 110 lb/yd² per inch is about 146.7 lb/ft³. Noted so the two conventions can be compared. This page stays on 145.