Road Base Calculator
Estimate the road base you need for a driveway or path in cubic yards and tons, from length, width, and depth.
Add a price per ton for delivered cost.
Road base, also called crushed aggregate base or sub-base, is the compacted layer of crushed stone and fines that goes under a driveway, path, patio, or paved surface. Get the quantity right and you avoid both the headache of running short mid-job and the waste of a half-used pile in the yard.
The math is volume: area times depth. Measure the length and width in feet, multiply for the square footage, then multiply by the depth. The one place people slip is units, since depth is almost always given in inches while length and width are in feet, so convert the depth to feet (inches divided by 12) before multiplying. That gives cubic feet, which divided by 27 gives cubic yards, the unit suppliers quote.
Aggregate is usually sold by weight, not volume. Compacted crushed road base runs roughly 1.4 US tons per cubic yard, so this calculator converts for you and also shows metric tonnes. Depths depend on the load: about 4 inches for a foot path, 6 to 8 inches for a car driveway, and 8 to 12 inches where trucks or heavy equipment will run.
Order extra. Road base compacts as you roll or tamp it, and the ground underneath is never perfectly flat, so most contractors add 10 to 15 percent. This tool builds in 10 percent so the “order this much” figure is the realistic one. Prices swing a lot by region and by haul distance, which is why the cost field is yours to fill in from a local quote rather than a number baked into the page. Punch in your supplier’s price per ton to see the delivered cost.
How we build and check this calculator
This calculator runs entirely in your browser, so the numbers you enter stay on your device. The math behind it is written by hand and tested against worked examples and standard references before the page goes live.
SuperGlobalCalculator is independently built and maintained. See how we build and verify our calculators.