Gravel Calculator
Estimate the gravel, crushed stone or aggregate you need by area and depth, then convert the result into volume, weight, bags and cost. Choose a clear metric or imperial input system and combine several project areas in one estimate.
Project inputs
Choose your measurement system first. Add one area or combine several areas such as a driveway, path and garden bed.
Optional settings: density, waste, price and bag weight
How to use, formulas, worked example, FAQs & related calculators
How to Use the Gravel Calculator
Choose metric or imperial units, select the shape of each area, enter the dimensions and depth, then add another area when a project has multiple sections. You can also enter a material density, waste allowance, price per tonne and bag weight to extend the estimate.
Gravel Calculator Formula
For a rectangular area:
For a circular area:
ToolVault sums all project areas before applying waste:
Estimated material weight is then:
How Much Gravel Do I Need?
Gravel quantity depends mainly on the covered area, depth and the material's bulk density. The calculator reports cubic metres, cubic yards and cubic feet so you can compare your result with a supplier's quoted unit. Because aggregate density varies with rock type, moisture and compaction, the density input should be replaced with supplier data when available.
Worked Example: Gravel for a Rectangular Driveway
Suppose a driveway is 10 m long, 5 m wide and 10 cm deep. The geometric volume is:
10 × 5 × 0.10 = 5.00 m³.
With a 10% waste allowance, the order volume is 5.50 m³. At an assumed density of 1.60 t/m³, the estimated weight is 8.80 tonnes. The calculator keeps these steps separate so changing the waste allowance or density does not change the underlying geometry.
Metric and Imperial Gravel Measurements
Metric mode uses metres for length and width and centimetres for depth. Imperial mode uses feet plus inches for length and width and inches for depth. Switching between systems converts the entered measurements instead of replacing them with unrelated defaults.
Gravel Coverage and Waste
Waste is a planning allowance for factors such as uneven ground, settlement, handling and small purchasing differences. It should not be confused with an increase in geometric depth. For a measured project, set the waste percentage according to the conditions and supplier guidance.
Bag Calculation
This calculator treats bag count as a product-specific quantity. When you enter the actual bag weight, the tool estimates how many bags correspond to the calculated material mass. Because bag contents and material density vary, the supplier's stated coverage or yield is preferable for packaged products.
Frequently Asked Questions
How do I calculate gravel volume?
Multiply the covered area by the required depth. For a rectangular area, multiply length × width × depth. For a circular area, calculate the circle's area first, then multiply by depth.
How deep should gravel be?
There is no single correct depth for every project. Driveways, walkways, drainage layers and decorative beds can require different depths based on design and site conditions.
How much does 1 cubic metre of gravel weigh?
It depends on the gravel type and condition. Use a supplier-provided bulk density whenever possible rather than relying on one universal number.
Should I add 10% waste?
Ten percent is a convenient planning example, not a universal rule. The correct allowance depends on project conditions, measurement accuracy and purchasing practice.