Calculators

Gravel Calculator

Tons and cubic yards of crushed stone, pea gravel or road base for a driveway, path or slab sub-base.

How it works

Aggregate is measured by area and depth but usually sold by the ton. Area times depth in feet gives cubic feet. An allowance covers compaction and waste. Multiplying by the material's density in pounds per cubic foot gives pounds, and dividing by 2,000 gives US tons. Densities vary by quarry, so treat the figure as a close estimate.

tons = length × width × (depth ÷ 12) × (1 + allowance) × density ÷ 2,000
density
About 100 lb/ft³ for crushed stone, 125 for compacted road base
allowance
10% for waste; 15–20% more if the base is compacted
2,000
Pounds in a US ton
27
Cubic feet in a cubic yard

Worked example

A 20 × 10 ft area, 4 inches of #57 crushed stone, 10% allowance, at $45 a ton.

  1. 1Area: 20 × 10 = 200 sq ft
  2. 2Volume: 200 × (4 ÷ 12) × 1.10 = 73.3 ft³ (2.72 yd³)
  3. 3Weight: 73.3 × 100 = 7,333 lb
  4. 4Tons: 7,333 ÷ 2,000 = 3.67 tons

Order about 3.7 tons, roughly $165 of stone before delivery.

Frequently asked questions

How much does a yard of gravel weigh?

Most gravel and crushed stone weighs 2,400–2,900 lb per cubic yard, or about 1.2–1.45 tons. Compacted road base and crusher run are heavier, about 3,000–3,400 lb. Wet material weighs more, which is one reason quarry tickets rarely match an estimate exactly.

How deep should gravel be for a driveway?

A new gravel driveway usually needs three layers totalling 8–12 inches: large base stone at the bottom, a middle layer of #57 or similar, and 2–3 inches of finer surface stone on top. Topping up an existing drive needs only 2–3 inches of the surface layer.

What gravel goes under a concrete slab?

Four to six inches of compacted crushed stone or road base. Angular stone locks together when compacted; round pea gravel rolls and does not. The base drains water away from the slab and gives it an even bearing surface, which prevents cracking.

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