Gravel Driveway Calculator

Order the Right Amount of Gravel the First Time

A gravel driveway is one of the most cost-effective surfaces you can install, but ordering the wrong amount is an expensive mistake. Come up short and you pay a second delivery fee; over-order and you have a pile of loose stone to spread or haul away. This gravel driveway calculator removes the guesswork by turning three simple measurements — length, width, and depth — into the exact tonnage, cubic yards, and material cost you need.

The Formula Behind the Numbers

The calculation is a straightforward volume problem with one unit conversion:

Area (ft²) = Length × Width Volume (ft³) = Area × (Depth in inches ÷ 12) Cubic Yards = Volume ÷ 27 Tons = Cubic Yards × 1.4

The depth is divided by 12 to convert inches to feet, and the volume is divided by 27 because there are 27 cubic feet in a cubic yard. The final step multiplies by 1.4, the approximate weight in US tons of one cubic yard of crushed gravel. The tool rounds tonnage and yards up to whole units, because suppliers sell in full increments and you never want to be short.

A Worked Example: A Standard Two-Car Driveway

Say you are surfacing a driveway that is 40 feet long, 12 feet wide, and you want 4 inches of gravel.

• Area = 40 × 12 = 480 ft²
• Depth in feet = 4 ÷ 12 = 0.333 ft
• Volume = 480 × 0.333 = 160 ft³
• Cubic yards = 160 ÷ 27 = 5.93, which rounds up to 6 yd³.
• Tons = 5.93 × 1.4 ≈ 8.3 tons, rounded up to 9 tons to be safe.

At a typical price of $30 per ton, that is roughly $249 for the exact 8.3 tons, or $270 if you round up to 9 tons, before delivery. Switch the price toggle to "per cubic yard" if your local quarry prices by volume instead.

Choosing Your Depth

Depth drives the entire order, so get it right:

• 2 inches — a thin top-up layer over an existing gravel surface.
• 4 inches — the standard for cars on an established base.
• 6 to 8 inches — needed for trucks, RVs, or a brand-new driveway with no sub-base.

Because tonnage scales directly with depth, going from 4 to 6 inches increases your order — and cost — by 50%. Measure carefully and don't pad the depth unless the traffic demands it.

Planning Delivery and Compaction

Most quarries deliver in tandem dump trucks carrying around 14 tons each, so the calculator also estimates the number of truckloads. This helps you anticipate delivery charges and clear enough space for the drop pile. Once spread, run a plate compactor or simply let traffic and a few rains settle the stone, then top up any low spots with your 10% buffer.

Pair It With Your Wider Project

If your driveway connects to a poured apron or pad, estimate that separately with the concrete calculator. Planning edging or a paved section instead? The asphalt calculator handles hot-mix tonnage the same way this tool handles gravel. With accurate numbers in hand, you can confidently compare supplier quotes and book a single, correctly sized delivery.