How much gravel do you need? Measured in tons, which is the moment a driveway project becomes real.
Use this free gravel calculator to estimate how many tons of gravel you need for a driveway, path, patio base, or drainage bed. Enter the area in square feet and the depth in inches, and get the weight in tons — the unit quarries and delivery trucks price by.
Gravel is sold by weight, planned by volume, and measured by area, which means every gravel project involves two conversions before anyone touches a shovel. This page does both and tells you what the truck will actually charge for.
What This Gravel Calculator Does
- Converts area × depth into tons of gravel
- Uses a density of about 1.4 tons per cubic yard, typical for crushed stone
- Works for driveways, walkways, French drains, shed pads, and paver bases
- Gives you a number to hand to a supplier instead of the phrase "a big pile"
How to Use the Gravel Calculator
Inputs:
- Area — in ft². Rectangles: length × width. Circular areas: 3.14 × radius². Odd shapes: split into rectangles and add
- Depth — in inches. 2–3" for a top-up or walkway, 4" for a paver base, 6–8" total for a new driveway in layers
Steps:
- Measure length and width in feet and multiply for area
- Choose the depth for your application (see the notes below)
- Click Calculate for tons
- Order 5–10% extra for compaction and spreading loss, and ask the supplier for the exact density of the stone you picked
How the Calculation Works
Cubic Yards = (Area ft² × Depth in ÷ 12) ÷ 27
Tons = Cubic Yards × 1.4
- Depth ÷ 12 converts inches to feet; ÷ 27 converts cubic feet to cubic yards; × 1.4 converts yards to tons
- Quick rule: 1 ton covers roughly 80–100 ft² at 2 inches deep
- Density varies by material: crushed stone 1.35–1.45 t/yd³ · pea gravel ~1.4 · sand ~1.35 · river rock ~1.3. Confirm with your quarry
- Gravel compacts 10–20% when rolled or driven on, so order above the calculated figure for anything load-bearing
Worked Example: 12 ft × 40 ft driveway at 4 inches
- Area = 12 × 40 = 480 ft²
- Cubic feet = 480 × (4 ÷ 12) = 160 ft³ → cubic yards = 160 ÷ 27 = 5.93 yd³
- Tons = 5.93 × 1.4 = 8.3 tons
- Add 10% for compaction → order 9 tons. That is a full tandem dump truck load, roughly 18,000 lb. Decide where it goes before it arrives, because it will not be moved twice.
Tips (From People Who Have Made These Mistakes)
- Build driveways in layers: 4" of coarse base stone, compacted, then 2" of finer topping. One deep layer of a single size never locks together
- Lay geotextile fabric under the base. It costs little and stops the stone from slowly migrating into the soil
- Delivery is usually cheaper per ton at 5+ tons. Below about 2 tons, bagged stone from a store can win once you count fuel and trips
- A cubic yard of gravel weighs roughly 2,800 lb — most half-ton pickups can legally carry about half a yard. Get it delivered
Frequently Asked Questions
How much gravel do I need for a driveway?
For a 12 × 40 ft driveway at 4 inches: about 8.3 tons (6 cubic yards). A full new driveway at 6–8 inches in layers needs 12–17 tons for the same footprint.
How many tons of gravel are in a cubic yard?
About 1.4 tons (2,800 lb) for typical crushed stone. Lighter materials like river rock run closer to 1.3, and wet material weighs more.
How much area does a ton of gravel cover?
Roughly 100 ft² at 2 inches, 70 ft² at 3 inches, or 50 ft² at 4 inches. Multiply out from there for larger projects.
How deep should gravel be?
2–3 inches for walkways and top-ups, 4 inches for a paver or shed base, and 6–8 inches in two layers for a driveway that carries vehicles without rutting.
Is gravel sold by weight or volume?
Usually by the ton in the US, though some suppliers quote cubic yards. Ask which one the price refers to — mixing them up changes the bill by about 40%.
Mini Roast Disclaimer
We roast the number, not you. Nine tons of stone is genuinely impressive. The wheelbarrow you were planning to use is not.
Reality Check
Density varies by stone type, size, and moisture, so tonnage is an estimate — confirm the actual figure with your supplier before ordering. Depth matters more than most people expect: under-building a driveway base produces ruts within a season, and the fix costs more than the extra stone would have.