Gravel Calculator
Enter the length and width of the area, the depth of gravel and the density your supplier quotes. The calculator gives the volume in cubic yards or cubic metres and the weight in tons or tonnes, which is how most suppliers sell it.
Answer
Gravel to order
1.04tons
0.741 cu yd of gravel at 1.4 t/cu yd.
- sq ft to cover
- 120
- cu yd of gravel
- 0.741
- tons
- 1.04
Check the work
Every line comes from the same calculation as the answer.
weight = length × width × depth × density
| depth | 2 ÷ 12 | 0.1667 ft |
|---|---|---|
| volume | 10 × 12 × 0.1667 | 20 cu ft |
| cubic yards | 20 ÷ 27 | 0.7407 cu yd |
| weight | 0.7407 × 1.4 | 1.037 tons |
How it works
Gravel is measured like any other layer: area times depth gives volume. A path 10 feet long and 12 feet wide laid 2 inches deep holds 120 × 0.1667 = 20 cubic feet, which is 0.74 cubic yards.
Most aggregate is sold by weight, though, and the weight of a cubic yard depends on the stone: its size, shape and how wet it is. That number is the density, and suppliers quote it for each product. The calculator multiplies the volume by the density you enter rather than assuming one for all gravel.
In the United States, weight is usually in short tons (2,000 lb) per cubic yard; elsewhere it is metric tonnes per cubic metre. Use the density in the same system you measured in.
Formula
volume = length × width × depth; weight = volume × density
The area is multiplied by the depth in the same unit to give the volume, and the volume is multiplied by the density to give the weight.
Worked examples
- Try these numbers
Garden path, 10 by 12 ft, 2 inches deep
- 2 inches is 0.1667 ft; 10 × 12 × 0.1667 = 20 cu ft.
- 20 ÷ 27 = 0.741 cubic yards.
- At 1.4 tons per cubic yard: 0.741 × 1.4 = 1.04 tons.
Order about 0.74 cu yd, which is 1.04 tons at this density.
- Try these numbers
Driveway in metres, 5 by 3 m, 5 cm deep
- 5 cm is 0.05 m; 5 × 3 × 0.05 = 0.75 m³.
- At 1.6 tonnes per m³: 0.75 × 1.6 = 1.2 tonnes.
Order 0.75 m³, about 1.2 tonnes.
- Try these numbers
One cubic metre exactly
- 2 × 1 m at 50 cm deep is 1 m³.
- At a density of 1 tonne per m³ the weight is 1 tonne.
1 m³ weighs 1 tonne at this density; real gravel is usually denser.
Inputs and results
- Length
- One side of the area, in feet or metres.
- Width
- The other side, in the same unit.
- Depth
- Thickness of the gravel layer, in inches or centimetres.
- Density
- Weight per volume quoted by the supplier: tons per cubic yard, or tonnes per cubic metre.
- Volume
- Area times depth, in cubic yards or cubic metres.
- Weight
- Volume times density, in tons or tonnes.
When to use it
- Ordering pea gravel for a garden path by the ton.
- Comparing a bulk bag against loose delivery for a driveway top-up.
- Checking how much extra stone a deeper base layer would need.
Common mistakes
- Using a density per cubic metre with measurements in feet, or per cubic yard with metres.
- Entering depth in feet when the field asks for inches: 2 inches is 2.
- Confusing US short tons (2,000 lb) with metric tonnes (1,000 kg) when comparing quotes.
What it does not do
- It covers rectangles of even depth; split a curved drive into rectangles and add the results.
- It does not know the density of a particular stone; use the supplier’s figure.
- It does not account for the extra volume a sub-base compacts into; enter the finished, compacted depth.
Method and assumptions
Depth is converted to the length unit (12 inches to the foot, 100 centimetres to the metre). Imperial volume is found in cubic feet and divided by 27 for cubic yards; the density per cubic yard is applied to that figure.
Weight is volume multiplied by density. No density is built in, because it differs between materials and suppliers.
Assumptions
- The area is a rectangle with an even, compacted depth.
- Density is the supplier’s figure for the stone you buy.
Edge cases
- A density of 0 or less is refused, since gravel always has weight.
- A depth of 0 gives no volume, so no answer is shown.
- Weights above a few tons usually arrive by truck; the volume is what fits the load.
Sources and corrections
This calculator uses an elementary formula, so it needs no outside data source. The method, the rounding rules and how a reported error is corrected are set out in the site standards.
Result looks wrong?
Send the inputs you used and the answer you expected. Every report is checked against the formula and its tests, and confirmed errors are corrected in public.