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 sell aggregate by the metric tonne (1,000 kg), so the volume is converted to weight using the density you enter (default 1,680 kg/m³, a typical value for compacted gravel — check your supplier's figure) and rounded up to the next quarter tonne.
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.
- Add 5% wastage: 1.44 × 1.05 = 1.512 m³.
- Convert to weight at 1,680 kg/m³: 1.512 × 1,680 = 2,540 kg = 2.54 tonnes.
- Round up to the ordering increment: 2.75 tonnes.
Order 2.75 tonnes. Enter your pit's quote per tonne and your provincial GST/HST rate for a cost estimate — rates differ by province.
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.
- Skipping wastage: compaction alone absorbs several percent, especially on new pads.
- 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 5% wastage that's 3.78 m³, which at 1,680 kg/m³ weighs about 6,350 kg = 6.35 tonnes — so order 6.5 tonnes.
My yard quotes in cubic yards — how do I compare?
The calculator shows the total volume; 1 cubic yard ≈ 0.765 m³, and at the default density a cubic yard weighs about 1.28 tonnes. Enter the price per tonne if that's how your supplier sells, or convert their per-yard price using those factors.
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:
- 2026-07-16
- Formula version:
- 1.0.0
- 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 wastage allowance is applied to the exact volume to cover compaction, settling and spreading losses.
- Weight = total volume × density. The density default of 1,680 kg/m³ is a clearly-labelled typical value for compacted gravel and is fully editable — actual density varies with stone type, size and moisture, so use your supplier's figure.
- Because gravel is usually sold by weight, the suggested order rounds the weight UP to the next 0.25 of the regional selling unit (US short tons in the US, metric tonnes elsewhere).
- The cost estimate simply multiplies the suggested order weight by the price you enter, then applies the tax rate you enter. No prices are built in.
- 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 default: 1,680 kg/m³ is a typical planning value for compacted gravel — editable; check your supplier's figure.
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.