🪨 Gravel Calculator
By ToolNimba Editorial Team · Updated 2026-06-19
Assumes a typical gravel density of about 1.4 US tons per cubic yard. Loose gravel, crushed stone, and wet material vary, so adjust the density to match your supplier's figure. The waste allowance covers spillage, compaction, and uneven ground.
This gravel calculator works out how much gravel you need to fill an area to a chosen depth. Enter the length, width, and depth of the space, and the tool returns the volume in cubic yards and cubic metres along with an estimated weight in tons. You can switch between imperial units (feet and inches) and metric units (metres), tune the gravel density to match your supplier, and add a waste allowance so you order enough to finish the job.
What is the Gravel Calculator?
Estimating gravel starts with volume. The space you are filling is a flat box, so its volume is simply length times width times depth. The only catch is keeping units consistent. In imperial work the length and width are usually in feet while the depth is in inches, so the depth is divided by 12 to turn it into feet before multiplying. The result is a volume in cubic feet, which is then divided by 27 (a cubic yard is 3 feet on each side, and 3 × 3 × 3 = 27 cubic feet) to give cubic yards, the unit most gravel suppliers quote.
Gravel is also sold by weight, so the calculator converts volume to tons using a density figure. Density is how much a unit of volume weighs, and for common dry gravel and crushed stone it sits around 1.4 US tons per cubic yard, although it varies with the stone type, particle size, and moisture. Multiplying the cubic yards by the density gives the weight in tons. The tool also shows metric tonnes for international suppliers, since one US ton is about 0.907 metric tonnes.
Real jobs are never perfectly flat or perfectly efficient, so it pays to order a little extra. Material is lost to spillage, gets pressed into soft or uneven ground, and compacts once it is raked and rolled. A waste allowance of around 10 percent is a sensible default for most driveways and paths. The calculator applies your chosen percentage on top of the bare volume so the order quantity already includes that cushion, which is cheaper than a second delivery for the last few square feet.
When to use it
- Working out how many cubic yards or tons of gravel to order for a driveway, path, or patio base.
- Filling a French drain, soakaway, or trench to a set depth with the right amount of stone.
- Budgeting a landscaping job by turning an area and depth into a concrete tonnage to price up.
- Checking a supplier or contractor quote by estimating the gravel volume and weight yourself.
How to use the Gravel Calculator
- Pick imperial units (feet and inches) or metric units (metres).
- Enter the length and width of the area, then the depth you want to fill.
- Adjust the gravel density if your supplier quotes a different tons-per-cubic-yard figure.
- Set a waste allowance percentage, then read off the volume in cubic yards and metres plus the weight in tons.
Formula & method
Worked examples
You are spreading gravel over a 20 ft by 10 ft driveway to a depth of 4 inches.
- Convert the depth to feet: 4 ÷ 12 = 0.3333 ft
- Volume in cubic feet = 20 × 10 × 0.3333 = 66.67 cubic feet
- Cubic yards = 66.67 ÷ 27 = 2.47 cu yd
- Cubic metres = 2.47 × 0.7646 = 1.89 cubic metres
- Weight = 2.47 × 1.4 = 3.46 US tons (about 3.14 metric tonnes)
- Add a 10% waste allowance: 2.47 × 1.10 = 2.72 cu yd, about 3.80 US tons to order
Result: ≈ 2.47 cu yd (1.89 cubic metres), ≈ 3.46 US tons, or about 2.72 cu yd and 3.80 tons once 10% waste is added.
You are filling a metric area 6 m long by 3 m wide to a depth of 0.1 m (10 cm).
- Volume in cubic metres = 6 × 3 × 0.1 = 1.8 cubic metres
- Cubic yards = 1.8 ÷ 0.7646 = 2.35 cu yd
- Weight = 2.35 × 1.4 = 3.30 US tons
- Convert to tonnes: 3.30 × 0.9072 = 2.99 metric tonnes
- Add a 10% waste allowance: 2.35 × 1.10 = 2.59 cu yd, about 3.63 US tons to order
Result: ≈ 1.8 cubic metres (2.35 cu yd), ≈ 3.30 US tons (2.99 tonnes), or about 2.59 cu yd and 3.63 tons once 10% waste is added.
Gravel needed to cover 100 square feet at common depths (density 1.4 tons per cubic yard)
| Depth | Cubic feet | Cubic yards | US tons |
|---|---|---|---|
| 2 in | 16.67 | 0.62 | 0.86 |
| 3 in | 25.00 | 0.93 | 1.30 |
| 4 in | 33.33 | 1.23 | 1.73 |
| 6 in | 50.00 | 1.85 | 2.59 |
Typical loose densities of common aggregates (approximate)
| Material | US tons per cubic yard | Metric tonnes per cubic metre |
|---|---|---|
| Dry gravel / crushed stone | 1.4 | 1.68 |
| Pea gravel | 1.3 | 1.55 |
| Sand (dry) | 1.3 | 1.55 |
| Wet gravel | 1.5 | 1.79 |
Common mistakes to avoid
- Mixing up the depth units. In imperial work the length and width are in feet but the depth is usually in inches. If you forget to divide the depth by 12, you overestimate the volume by twelve times. Keep every measurement in the same unit before multiplying, or let the calculator handle the conversion for you.
- Treating one density figure as fixed. Around 1.4 tons per cubic yard is a fair average for dry gravel, but pea gravel is lighter and wet or compacted stone is heavier. If your supplier publishes a density, use it, because a 10 percent density error feeds straight through to the tonnage you order and pay for.
- Ordering the exact volume with no spare. Bare volume assumes perfect ground and zero loss. In practice gravel spills, sinks into soft soil, and settles when compacted. Skipping the waste allowance often leaves you a few square feet short, and a top-up delivery can cost more than the extra material itself.
- Confusing US tons with metric tonnes. A US (short) ton is 2,000 pounds while a metric tonne is about 2,205 pounds, so they differ by roughly 10 percent. Check which one your supplier quotes before comparing prices, since the calculator shows both figures side by side.
Glossary
- Cubic yard
- A volume measuring 3 feet on each side, equal to 27 cubic feet. The unit most gravel suppliers use for ordering.
- Density
- How much a unit of volume weighs. For gravel it is usually given in tons per cubic yard or tonnes per cubic metre.
- US ton
- A short ton equal to 2,000 pounds, about 0.907 metric tonnes. Common in the United States.
- Metric tonne
- A unit of 1,000 kilograms, about 2,205 pounds, used by most suppliers outside the United States.
- Waste allowance
- An extra percentage added to the calculated volume to cover spillage, compaction, and uneven ground.
Frequently asked questions
How much gravel do I need?
Multiply the area length by its width and by the depth (in matching units) to get the volume, then convert to cubic yards by dividing cubic feet by 27. For a 20 by 10 foot area at 4 inches deep that is about 2.47 cubic yards. The calculator does this instantly and also adds a waste allowance.
How do I convert cubic yards of gravel to tons?
Multiply the cubic yards by the gravel density. A common figure for dry gravel and crushed stone is about 1.4 US tons per cubic yard, so 2.47 cubic yards weighs roughly 3.46 tons. Adjust the density in the calculator to match your supplier for a more exact result.
What density does this gravel calculator assume?
It defaults to about 1.4 US tons per cubic yard, a typical value for dry gravel and crushed stone. Pea gravel is a little lighter and wet or heavily compacted stone is heavier, so you can change the density field to whatever your material supplier publishes.
How deep should a gravel layer be?
A decorative gravel top layer is often 2 to 3 inches deep, while a driveway base typically needs 4 to 6 inches, sometimes more over soft ground. Choose the depth your project calls for and the calculator works out the matching volume and tonnage.
Why should I add a waste allowance?
Real ground is uneven and some material is always lost to spillage and compaction, so the bare volume usually falls short. A waste allowance of around 10 percent gives a small cushion so you do not run out near the end and need a costly extra delivery.
Does this work for crushed stone, sand, or pea gravel?
Yes. The volume calculation is the same for any loose material that fills an area to a depth. To get an accurate weight, just set the density field to the value for your material, since sand, pea gravel, and crushed stone each weigh slightly differently per cubic yard.