What is the Crushed Stone Calculator?
This tool estimates how much crushed stone you need to fill a rectangular area, such as a driveway, walkway, patio base or trench backfill. Enter the length and width in feet, the depth in inches, and the material density, and it returns the volume in cubic feet and cubic yards plus the total weight in US tons — the unit most suppliers sell by.
How to use it
Measure the area you want to cover. Decide on a depth (2–4 inches is common for a finished stone layer, more for a base course). Enter all three dimensions and the density. Crushed stone typically weighs about 100 lb per cubic foot (≈ 1.35 tons per cubic yard), but compacted or denser material can run higher, so adjust if your supplier provides a figure.
The formula explained
First the area is multiplied by depth (converted from inches to feet) to get cubic feet of volume. Multiplying volume by density gives the weight in pounds, and dividing by 2000 converts pounds to US tons:
$$\text{tons} = \text{L} \times \text{W} \times \left(\text{D} \div 12\right) \times \text{density} \div 2000$$
Worked example
A driveway 20 ft long and 10 ft wide filled to 4 inches deep with stone at 100 lb/ft³: $$\text{volume} = 20 \times 10 \times (4/12) = 66.67 \text{ ft}^3.$$ $$\text{Weight} = 66.67 \times 100 = 6667 \text{ lb}.$$ $$\text{Tons} = 6667 \div 2000 \approx 3.33 \text{ tons}$$ (about 2.47 cubic yards).
FAQ
What density should I use? Crushed stone commonly ranges 95–105 lb/ft³. Use 100 as a safe default unless your supplier states otherwise.
Should I order extra? Yes — add roughly 5–10% for compaction and waste, especially when building a base layer.
Are these US (short) tons? Yes, the result uses the 2000 lb US short ton.
