Gravel Calculator
Find how much gravel you need for a driveway, path or drainage trench. Enter the area and depth to get the volume in cubic yards and the weight in tons, with a waste allowance.
Gravel needed
Assumes ~1.4 tons per cubic yard. A 50 lb bag holds about 0.5 ft³.
How to calculate gravel
Gravel is estimated from the area you want to cover and the depth of the layer. First find the area in square feet: length times width for a rectangle, or π times the radius squared for a circular pad. Multiply the area by the depth converted to feet (depth in inches ÷ 12) to get the volume in cubic feet, then divide by 27 to reach cubic yards. The formula is cubic yards = area (ft²) × depth (in) ÷ 12 ÷ 27. The calculator above does this and also converts the volume to weight.
Gravel is usually sold by weight, so the volume is converted to tons using its density. Construction gravel weighs roughly 1.4 US tons per cubic yard, or about 2,800 pounds, though wet or especially dense stone can be heavier. If your supplier quotes a different density for the specific product, scale the tonnage accordingly.
Depth guide for common jobs
Depth drives the whole estimate, so it is worth getting right. A gravel driveway is typically 4 to 6 inches total, often built as a coarse base course with a finer top course. Garden paths and walkways need about 2 to 3 inches. A French drain or drainage trench is sized to the trench itself. Because coverage halves every time you double the depth, one ton that covers 100 square feet at 2 inches covers only 50 square feet at 4 inches. Calculate from your real depth rather than a generic coverage figure.
Ordering by the yard or the ton
Your project needs a certain volume (cubic yards), but many suppliers price and deliver by weight (tons). The calculator gives both from the same measurements, so you can order in whichever unit your yard uses and check the two line up. For small top-ups, bagged gravel is sold in roughly 0.5 ft³ (about 50 lb) bags, and the bag count above helps you decide between bags and a bulk load.
Add a small waste allowance
Gravel settles and compacts, and spreading is never perfectly even, so a 5 percent allowance is sensible for most jobs. For a driveway that will be compacted in layers, 5 to 10 percent is reasonable. If you are also laying a sub-base under pavers or concrete, size the bedding layer with the sand calculator and any slab on top with the concrete calculator.