Gravel Calculator
Measure the area, set the depth, and get the gravel you need in cubic yards, cubic metres or bags. Weight is only estimated if you tell us the density your supplier quotes.
Switching units keeps your measurements. Nothing is reset.
Areas
Depth
How deep the finished layer should be.
How are you buying it?
Waste allowance
10% allows for settling and for the low spots that always appear once you start raking.
Offcuts, breakages, pattern matching and the occasional damaged piece all mean you use more material than the bare area. Keeping a few spare pieces for future repairs is also normal.
This is a planning allowance, not a rule. Adjust it for your layout, your material and your own tolerance for a second trip to the store.
Weight (optional)
Only your supplier can tell you this. Leave it empty and no weight is estimated.
Estimated cost
Cost uses the price you enter. This product never shows invented market prices.
Your result appears here
Enter your measurements to see how much material to buy.
How to use this calculator
- 1
Measure the area to be covered. A driveway with a turning area is two rectangles; add a second area rather than averaging.
- 2
Set the depth of the finished layer. Put it in the inches box: a four inch layer is 0 ft 4 in, not 4 ft.
- 3
Choose bulk if a supplier is delivering by the yard or tonne, or bags if you are collecting it yourself, and enter what one bag holds.
- 4
If your supplier sells by weight, enter the bulk density they quote and the weight appears alongside the volume.
A worked example
A 20 ft × 10 ft driveway at 4 in deep, with a 10% overage for settling:
Measured volume
66.67 ft³66.67 ft³
Add the overage
66.67 ft³ × 1.173.33 ft³
Convert to the unit you order in
73.33 ft³2.72 yd³
You will need
2.72 yd³
This example is produced by running the calculator above, so it always matches what the tool does.
The formula
Volume is area × depth. The overage is applied to that volume, and the result is converted into cubic yards or cubic metres for ordering. When a density is supplied, weight is volume × density; without one, no weight is shown, because bulk density varies too much between stone types, gradings and moisture levels to guess at.
Ordering gravel
Depth depends on what the surface carries
A decorative path needs far less than a drive that takes a car, and a drive over soft ground needs a separate sub-base under the visible layer. Ask your supplier what depth suits the traffic and the ground you have.
Tonnes and yards are not interchangeable
Suppliers quote by weight in some markets and by volume in others, and converting between them needs the density of that specific stone. This calculator will do it, but only with a figure you have been given.
Order slightly long, not slightly short
A second delivery usually costs more than the extra material would have. Gravel also settles into low spots you cannot see until you start raking, which is what the overage is for.
Common questions
- How many cubic yards of gravel do I need?
- Multiply the area in square feet by the depth in feet, then divide by 27. A 200 square foot area at four inches deep is 200 × 0.333 = 66.7 cubic feet, or about 2.5 cubic yards.
- How much does a cubic yard of gravel weigh?
- It depends on the stone, its grading and how wet it is, which is why no figure is assumed here. Your supplier can give you the density for the specific product; enter it and the weight is calculated from your volume.
- Do I need a sub-base as well?
- Often, for anything carrying vehicles. That is a separate layer of a different material at its own depth, so calculate it as a second job rather than adding depth to the decorative layer.