How Much Gravel Do I Need? Cubic Yards, Tons and Depth by Project

Multiply length × width × depth (in feet), divide by 27 for cubic yards, then multiply by about 1.4 tons per cubic yard: a 10 ft × 10 ft area 3 in deep is 0.93 cubic yards, or about 1.3 tons.

That is 25 cubic feet, converted to tons at 1.4 tons per cubic yard, a typical figure for crushed stone and not a standard. Your supplier’s figure replaces it.

How do you calculate how much gravel you need?

1. Find the area. Length × width in feet. Split odd shapes into rectangles and add them.
2. Choose the finished depth. If you spread two layers, add their depths together. Convert inches to feet by dividing by 12.
3. Find the volume in cubic feet. Area × depth (ft).
4. Convert to cubic yards. Divide by 27.
5. Add a compaction allowance if the gravel will be compacted, then round up.
6. Convert to tons by multiplying the loose cubic yards by the tons per cubic yard for your stone. Ask your supplier for that number.

cubic yards = length (ft) × width (ft) × depth (in) ÷ 12 ÷ 27
order (cubic yards) = cubic yards × (1 + compaction %)
tons = order (cubic yards) × tons per cubic yard

Gravel is a bulk material, so this is the same volume method used for soil and mulch. The general version, with circles and triangles, is in how to calculate cubic yards.

How much gravel per 100 square feet?

Scale the rows below by your area. The tons column assumes 1.4 tons per cubic yard and no compaction allowance, so replace it with your supplier’s figure.

How deep should gravel be? There is no single standard depth. Guides commonly quote 2 to 4 inches for a gravel surface layer, but the right depth for a driveway, path, patio base or drainage trench depends on the ground underneath, the traffic, drainage and local rules. Take the depth from your plans, your contractor or your local building or road department, then use the table to price it.

How many tons are in a cubic yard of gravel?

A cubic yard of loose, dry crushed stone weighs about 1.4 to 1.5 short tons (2,800 to 3,000 lb). Weight changes with the type of rock, how it is graded and how wet it is, and no government or manufacturer standard sets one value for “gravel.” The figures below are typical ranges from supplier-style references, so use them for planning and replace them with your supplier’s numbers when you order.

Confidence: medium to low. These ranges come from a supplier-style reference page, not from a standard, and wet material can weigh 15% to 20% more. The full table for sand, soil and concrete is in how many cubic yards are in a ton. Tons here are US short tons of 2,000 lb.

How far does a ton of gravel go?

One cubic yard covers 324 ÷ depth (in) square feet. A ton covers more or less than that depending on the weight per yard. At 1.4 tons per cubic yard, one ton is 27 ÷ 1.4 = 19.286 cubic feet, and its coverage is 19.286 ÷ (depth in feet).

Compaction allowance

Loose gravel packs down once it is spread and compacted, so you order more than the finished volume. Many guides suggest adding roughly 10% to 20% for compaction and settlement. The BuildLumi gravel calculator starts at 15%. That is a convention, not a measured value, so lower it for a loose decorative layer and raise it for a thick compacted base. Avoid adding a separate spillage percentage on top unless you want both.

Worked example: a driveway

A driveway is 50 ft × 10 ft with a 4 in base and a 2 in top layer, both crushed stone at 1.4 tons per cubic yard, with 15% for compaction.

• Base: 50 × 10 × (4 ÷ 12) = 166.667 cubic feet = 6.1728 cubic yards
• Top layer: 50 × 10 × (2 ÷ 12) = 83.333 cubic feet = 3.0864 cubic yards
• Total: 250 cubic feet = 9.2593 cubic yards
• With 15% compaction: 9.2593 × 1.15 = 10.648 cubic yards
• Weight: 10.648 × 1.4 = 14.91 tons, which is 29,815 lb or 13.52 metric tonnes

A smaller job: a 20 ft × 12 ft pad, 3 in deep, is 240 × 0.25 = 60 cubic feet = 2.2222 cubic yards, and 2.2222 × 1.4 = 3.11 tons with no compaction allowance.

Ordering by the ton or by the yard

Your supplier decides whether gravel is sold by weight or by volume, and some quote both. Ask for the price unit, the tons per cubic yard of the exact stone, any minimum load and whether the delivery weight will be on a scale ticket. Using one density for both numbers keeps the quote consistent. If you order by the ton but calculate by the yard, divide the tons by the density to compare.

Common mistakes

• Using one weight for every stone. Pea gravel, crushed stone and crusher run weigh different amounts per cubic yard.
• Ordering the finished volume. Compacted gravel loses volume, so the last stretch comes up thin.
• Forgetting inches to feet. A 4 in layer uses 4 ÷ 12 ft in the formula.
• Mixing up tons and tonnes. A US ton is 2,000 lb. A metric tonne is 1,000 kg, about 2,204.6 lb.
• Stacking allowances. Adding compaction and a large waste percentage on top of each other over-orders.

Questions people ask