How many tons of gravel do I need?

Multiply length × width × depth (all in feet) to get cubic feet, divide by 27 for cubic yards, then multiply by the weight per cubic yard. A driveway 40 ft × 10 ft covered 4 inches deep is 400 × 0.3333 = 133.33 cu ft = 4.94 cu yd; at 1.4 tons per cubic yard that is 6.91 tons.

How much does a cubic yard of gravel weigh?

It depends on the stone, the size and grading of the pieces, how wet it is and whether it is compacted. This calculator uses 1.4 tons (2,800 lb) per cubic yard as a planning value for loose gravel and crushed stone, but your supplier’s own figure is always better — type it into the density box.

How much area does a ton of gravel cover?

At 1.4 tons per cubic yard, one ton is 27 ÷ 1.4 = 19.29 cu ft. Spread 2 inches deep that covers about 116 sq ft, at 3 inches about 77 sq ft, and at 4 inches about 58 sq ft. A denser material covers less.

What is the difference between a ton and a metric ton?

A US (short) ton is exactly 2,000 lb, or 907.18474 kg. A metric ton (tonne) is 1,000 kg, about 2,204.6 lb. To convert, multiply US tons by 0.90718474 to get metric tons. The calculator shows both.

How thick should the gravel base under a concrete slab be?

For concrete slab-on-ground floors, the International Residential Code generally calls for a base course at least 4 inches thick of clean graded sand, gravel or crushed stone (section R506.2.2), with exceptions depending on the soil. Driveway and patio bases depend on your soil, climate and use, so follow your plans or local contractor.

Gravel Calculator — Tons & Cubic Yards Needed

Estimate how much gravel, crushed stone or sand you need in cubic yards and tons from the area and depth, using your supplier’s density or a planning value, with a delivery cost estimate.

How to use the gravel calculator

Add each area you are covering — a driveway, a path, a patio base — as a rectangle, circle or triangle, with lengths in feet and inches. Enter the depth of stone in inches, then pick the material. Choosing a material fills in a planning density; if your supplier gives you a weight per cubic yard (or per cubic meter), type it into the density box instead, which is the single biggest improvement you can make to the estimate.

The result gives tons (US short tons), cubic yards, cubic feet and pounds, plus metric tons and cubic meters. Add a price per ton or per cubic yard — however your supplier quotes it — to see the cost. The working shows each step with your numbers, and the page address keeps your inputs so you can share them with a supplier or contractor. Nothing leaves your browser.

The formula

volume (cu ft) = area (sq ft) × depth (in) ÷ 12
cubic yards = cubic feet ÷ 27
tons = cubic yards × density (tons per cubic yard)
pounds = tons × 2,000
metric tons = tons × 0.90718474

The areas are length × width for a rectangle, π × (diameter ÷ 2)² for a circle and ½ × base × height for a triangle. Keep the units consistent: 4 inches of depth is 4 ÷ 12 = 0.3333 ft, not 0.4 ft.

Worked example

The calculator opens with a driveway 40 ft long and 10 ft wide, covered with 4 inches of crushed stone:

Area: 40 × 10 = 400 sq ft.
Volume: 400 × 0.3333 ft = 133.33 cu ft, and 133.33 ÷ 27 = 4.94 cubic yards.
Weight: 4.9383 × 1.4 = 6.91 tons, which is 13,827 lb or 6.27 metric tons.
Cost: at $45.00 per ton (an illustration, not a typical price), 6.9136 × $45.00 = $311.11.

Density: the number that matters most

Stone is sold by volume or by weight, and converting between them needs the material’s bulk density — its weight per cubic yard including the air gaps between pieces. That figure is not fixed. It changes with the type of rock, the size and mix of particle sizes, how wet the material is (wet sand is heavier than dry) and whether it has been compacted. State transportation departments that buy aggregate by the ton use conversion factors for each material for exactly this reason; Wisconsin DOT has published a research report on weight–volume relationships for soils and aggregates.

The presets here are rough planning values, not measurements: 1.4 tons per cubic yard for crushed stone, pea gravel and river rock, 1.35 for dry sand, 1.6 for wet sand and 1.85 for compacted road base. Treat the result as a starting point, ask your supplier for the density of the exact product, and type it in. In metric mode the density box uses metric tons per cubic meter; 1 ton per cubic yard equals about 1.187 metric tons per cubic meter.

Loose vs. compacted

Crushed stone and road base are often compacted after spreading, which squeezes out air: the same weight then fills less volume. If you measure the finished, compacted depth, either use a compacted density (the Road base, compacted preset or your supplier’s compacted figure) or add an extra allowance to a loose density. Decorative gravel such as pea gravel and river rock is normally left loose, so a loose density fits.

Tips before you order

Confirm how the supplier sells it. By the ton, by the cubic yard or by the bag — and whether a “ton” means 2,000 lb. Use the matching price unit.
Measure depth after digging. Excavations are rarely even. Take several depth readings and use the average.
Split odd shapes. A curved path or a driveway with a turnaround can be added as several rectangles, triangles and circles.
Ask about delivery. Trucks have load limits and many suppliers charge for delivery, so it can pay to order everything at once.

Pouring a slab on the base? The concrete calculator works out the cubic yards and bags. For planting beds, use the mulch calculator, and for irregular areas the square footage calculator. For conversions, see metric tons to kilograms, kilograms to pounds and cubic feet to cubic meters.

Last reviewed 25 September 2026 · Built and checked by the Reeliy team · How we test our tools

Gravel Calculator

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