What is the Gravel Driveway Calculator?
This tool estimates how much gravel you need to surface or fill a driveway. From the area's length and width plus the desired depth, it computes the volume and converts it into weight using the gravel's density. Results are given in US tons, cubic yards, cubic feet and pounds so you can order material in whatever unit your supplier uses.
How to use it
Enter the driveway length and width in feet, the gravel depth in inches, and the gravel density in pounds per cubic foot. Typical crushed gravel weighs about 95–105 lb/ft³. Press calculate and you'll see the total tonnage plus the volume in cubic yards and cubic feet.
The formula explained
First the depth in inches is converted to feet by dividing by 12. Volume (cubic feet) = length × width × (depth ÷ 12). Multiply that volume by the density to get pounds, then divide by 2000 (pounds per US ton) to get tons. Cubic yards come from dividing cubic feet by 27.
$$\begin{gathered} \text{Tons} = \frac{V \times \text{Density}}{2000} \\[1.5em] \text{where}\quad \left\{ \begin{aligned} V &= \text{Length} \times \text{Width} \times \frac{\text{Depth (in)}}{12} \end{aligned} \right. \end{gathered}$$
Worked example
A 40 ft × 12 ft driveway at 4 in depth: depth = \(4/12 = 0.3333\) ft. Volume:
$$V = 40 \times 12 \times 0.3333 = 160 \text{ ft}^3 = 5.93 \text{ cubic yards}$$
At 100 lb/ft³, weight:
$$160 \times 100 = 16{,}000 \text{ lbs} = 8 \text{ US tons}$$
FAQ
What density should I use? Crushed stone and pea gravel are usually 95–105 lb/ft³. Check with your supplier for the exact product.
How deep should driveway gravel be? A typical base layer is 3–4 inches; multiple layers for a new driveway may total 6–8 inches.
Are these US tons? Yes, this calculator uses the US short ton of 2000 pounds.
