Landscaping
Gravel Calculator
Enter the area in metres (or feet) and the depth in centimetres to get the cubic metres and metric tonnes of gravel to order, with wastage and an optional cost estimate.
Formula tested · Local units · No sign-up
Project inputs
Enter measurements
Use your preferred units. Results update automatically.
Show the calculation methodFormula, conversions, rounding, and assumptions+
Volume = length × width × depth, converted to metres before multiplying — an 8 cm layer over 6 m × 3 m is 6 × 3 × 0.08 = 1.44 m³.
Canadian pits and yards commonly sell aggregate by the metric tonne (1,000 kg). The calculator uses the density you enter and rounds only when the current quote supplies a tonne increment.
Real-world example
Worked example: 6 m × 3 m parking pad, 8 cm deep
- Convert depth: 8 cm = 0.08 m.
- Volume: 6 × 3 × 0.08 = 1.44 m³.
- For this example, enter a 5% allowance: 1.44 × 1.05 = 1.512 m³.
- Enter the example density of 1,680 kg/m³: 1.512 × 1,680 = 2,540 kg = 2.54 tonnes. Replace it with the selected pit product's density.
- Enter the example supplier increment of 0.25 tonne: 2.54 rounds up to 2.75 tonnes.
The example order is 2.75 tonnes only with the entered 5% allowance, 1,680 kg/m³ density and 0.25-tonne quote increment.
Before you start
How to measure
- Measure in metres or feet — the calculator accepts both per field; a 20 ft × 10 ft pad can stay in feet while the depth stays in centimetres.
- Depth depends on use: a few centimetres for decorative cover, more (in compacted lifts) for driveways and pads that carry vehicles through freeze–thaw cycles.
- If frost heave is a concern, the granular base build-up matters more than the top course — treat each layer as its own calculation.
Local guidance
Notes for Canada
- Canadian aggregate is sold by the metric tonne, though some yards still quote small quantities by the cubic yard — the calculator shows volume and both weight units so you can compare.
- Common products go by names like 3/4-inch crush, screened gravel or A-gravel depending on the province; densities differ, so use your supplier's figure.
- Sales tax is 5% GST plus provincial tax or a combined HST depending on the province — enter your combined rate.
Quick reference
Gravel depth quick reference (typical planning values)
| Application | Common depth |
|---|---|
| Decorative cover over fabric | 5–8 cm (2–3 in) |
| Garden paths | 8–10 cm (3–4 in) |
| Driveway top course | 8–10 cm over a compacted base |
| Driveway including granular base | 20–30 cm total, compacted in lifts |
Planning values only — frost-susceptible ground needs a proper granular build-up.
Good to know
Common mistakes to avoid
- Mixing unit systems mid-calculation — a depth of 3 (inches) entered as 3 cm understates the gravel by more than half.
- Confusing metric tonnes with US short tons when reading American how-to guides — Canadian suppliers sell metric.
- Treating a generic wastage percentage as a compaction conversion. Ask the supplier for the selected product's loose-to-compacted factor.
- Ordering the top course depth for the whole build-up when a driveway also needs a granular base layer.
Need help?
Frequently asked questions
How many tonnes for a 12 m × 3 m driveway at 10 cm?
12 × 3 × 0.1 = 3.6 m³. With an entered 5% allowance and 1,680 kg/m³ density, that becomes about 6.35 tonnes. It rounds to 6.5 tonnes only when you enter a 0.25-tonne quote increment.
My yard quotes in cubic yards — how do I compare?
The calculator shows total volume; 1 cubic yard is about 0.765 m³. Convert it to weight only with the selected supplier product's density, then compare prices on the same sale-unit basis.
Is a tonne of gravel the same as a ton?
No. A metric tonne is 1,000 kg; a US short ton is 907 kg. Canadian suppliers use metric tonnes, so a US guide saying '5 tons' means about 4.5 tonnes.
Keep planning
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About this calculator
- Written by:
- BuildMeasure Editorial Team
- Technically reviewed by:
- Pending independent technical reviewer (formula unit-tested; see methodology)
- Last reviewed:
- 2026-07-23
- Formula version:
- 1.1.0
- Region reviewed for:
- Canada
- Spotted an error?
- Report a correction
Methodology
- Volume is computed as length × width × depth, converted internally to SI units (metres) before any arithmetic to avoid unit drift.
- The optional wastage allowance is applied to exact finished volume for handling and uneven spreading. It is not a loose-to-compacted conversion; obtain that separately for the selected aggregate and method.
- Weight = total volume × the bulk density you enter for the exact product and condition. No default density is supplied because stone type, grading, moisture and loose or compacted state change the conversion.
- Supplier rounding occurs only when you enter the mass increment shown on the current quote. If the increment is blank, the calculator reports the unrounded calculated weight.
- The preliminary material subtotal multiplies calculated or supplier-rounded weight by the price you enter. Tax is added only after you confirm that the entered price excludes tax and provide a rate; an unresolved basis does not produce a final total.
- The formula is covered by automated unit tests, including hand-calculated worked examples, and is versioned (see formula version on this page).
Sources & standards
- Unit definitions: 1 tonne = 1,000 kg; 1 US short ton = 907.18474 kg; 1 yd³ = 0.764554857984 m³ (exact definitions).
- Density boundary: Weight is calculated only from the entered pit or supplier density; no universal density or order increment is assumed.
This tool provides a material estimate for planning purposes only. It is not a quotation, and the weight conversion depends on the density you enter — stone type and moisture change it. Confirm quantities and density with your supplier before ordering.