How much gravel do I need?
Enter the size of the area and how deep you want the gravel. See the volume in cubic yards, the weight in tons, and the cost if you enter a price.
- Gravel
- 2.47 yd³
Covering the area 4 in deep takes 2.47 yd³ of gravel, about 3.5 ton.
- Cubic feet
- 66.7 ft³
- Cubic metres
- 1.89 m³
- Weight in tons
- 3.5 ton
- Weight in tonnes
- 3.18 t
Gravel: 2.47 yd³. Covering the area 4 in deep takes 2.47 yd³ of gravel, about 3.5 ton.
How to calculate
Computes the volume of gravel for a rectangular or round area at a depth, in cubic yards and cubic metres, its weight in tons at a bulk density, and the cost.
Example with the default inputs (Area shape Rectangle, Length 20 ft, Width 10 ft, Depth 4 in, Density 105 lb/ft³, Price per Ton (2,000 lb)): Covering the area 4 in deep takes 2.47 yd³ of gravel, about 3.5 ton.
Method: volume = area × depth; weight = volume × density; cubic yards = cubic feet ÷ 27; tons = pounds ÷ 2,000
- Rectangle: length × width. Circle: π × diameter² ÷ 4.
- The default density is dry gravel, 105 lb/ft³ (1,680 kg/m³), from the Engineering ToolBox. Wet gravel is about 125 lb/ft³. Ask your supplier for the density of their stone.
- The volume is the loose volume of the layer. It adds nothing for compaction or waste.
Worked examples
Each example is checked against the calculator on every build.
- Area shape Rectangle, Length 20 ft, Width 10 ft, Depth 4 in, Density 105 lb/ft³, Price per Ton (2,000 lb), Price $40.00 gives Cubic feet 66.7 ft³, Weight in tons 3.5 ton, Cost $140.00.Source: hand calculation in content.mdx: 20 × 10 × 4/12 = 66.67 ft³ = 2.47 yd³; × 105 lb/ft³ = 7,000 lb = 3.5 tons; × $40 = $140
- Area shape Circle, Diameter 12 ft, Depth 3 in, Density 105 lb/ft³, Price per Cubic yard, Price $55.00 gives Cubic feet 28.3 ft³, Cost $57.60.Source: hand calculation in content.mdx: π × 12² ÷ 4 × 0.25 = 9π = 28.27 ft³ = 1.047 yd³; × $55 = $57.60
- Area shape Rectangle, Length 32.81 ft, Width 9.843 ft, Depth 3.937 in, Density 104.9 lb/ft³, Price per Tonne (1,000 kg), Price $50.00 gives Cubic metres 3 m³, Weight in tonnes 5.04 t, Cost $252.00.Source: hand calculation in content.mdx: 10 × 3 × 0.1 = 3 m³; × 1,680 kg/m³ = 5,040 kg = 5.04 t; × $50 = $252
How it works
- Area: rectangle = length × width; circle = π × diameter² ÷ 4.
- Volume = area × depth. Cubic yards = cubic feet ÷ 27.
- Weight = volume × density. Tons = pounds ÷ 2,000 (US short tons). Tonnes = kilograms ÷ 1,000.
- Cost = the weight in tons or tonnes, or the volume in cubic yards, × the price.
The default density is 105 lb/ft³ (1,680 kg/m³), the Engineering ToolBox value for dry gravel. Wet gravel is about 125 lb/ft³. Crushed stone, pea gravel and river rock vary, so use your supplier's figure when you have it.
The volume is the loose volume of the layer, with nothing added for compaction or waste.
Worked examples by hand
A 20 ft × 10 ft area, 4 in deep, at $40 a ton. 4 in = 1/3 ft. 20 × 10 × 1/3 = 66.67 ft³ = 66.67 ÷ 27 = 2.47 yd³. The weight is 66.67 × 105 = 7,000 lb = 3.5 tons. The cost is 3.5 × 40 = $140.
A round bed 12 ft across, 3 in deep, at $55 a cubic yard. π × 12² ÷ 4 × 0.25 = 9π = 28.27 ft³ = 1.047 yd³. The cost is 1.047 × 55 = $57.60.
A 10 m × 3 m path, 10 cm deep, at 1,680 kg/m³ and $50 a tonne. 10 × 3 × 0.1 = 3 m³. 3 × 1,680 = 5,040 kg = 5.04 t. The cost is 5.04 × 50 = $252.
Other questions people ask
How do I calculate how much gravel I need?
Multiply length × width × depth, all in feet, for cubic feet, and divide by 27 for cubic yards. A 20 ft × 10 ft area 4 in deep is 20 × 10 × 4/12 = 66.67 ft³, or 2.47 cubic yards.
How many tons of gravel are in a cubic yard?
At the dry gravel density of 105 lb/ft³, a cubic yard (27 ft³) weighs 27 × 105 = 2,835 lb, or 1.42 tons. Wet gravel, at about 125 lb/ft³, weighs 3,375 lb, or 1.69 tons.
How deep should gravel be?
It depends on the job and the stone size. Paths and decorative beds are often a few inches deep; driveways are built in layers of larger base stone topped with smaller stone. Follow your supplier’s or designer’s depth for your use.
Why does the supplier’s tonnage differ from mine?
Gravel is sold by weight, and its density depends on the stone, its size and how wet it is. Ask the supplier for the density of the product and type it under Weight and cost.
Should I order extra gravel?
The volume here is the exact loose volume. Gravel settles and compacts under traffic and some spreads past the edges, so many people round up to the next whole ton or yard.
How do I work out a round area?
Choose Circle and enter the diameter. The area is π × diameter² ÷ 4, so a 12 ft circle is 113.1 ft².