How to read the result
- Yards or tons: some suppliers sell gravel by volume (cubic yards or cubic metres) and others by weight (tons or tonnes). The calculator gives both; the weight depends on the density you enter.
- Round up: suppliers deliver in set amounts, such as whole or half yards. Round the result up to the next amount they sell.
- Compacted depth: if the depth you need is the depth after compaction, the loose gravel delivered will be more. Enter a loose-to-compacted factor above 1 from your supplier or specification.
The default density is the Caterpillar Performance Handbook's loose weight for dry gravel, 1/4 in to 2 in. Real gravel varies with rock type, size grading and moisture, so use your supplier's figure for the product you are ordering when you have it.
Worked example
A path 20 ft long and 10 ft wide needs gravel 4 in deep, with 5% extra for waste. The density is 1,690 kg/m³ (105.5 lb/ft³), the handbook figure for dry 1/4 in to 2 in gravel.
- Area = 20 × 10 = 200 ft²
- Volume = 200 ft² × (4 ÷ 12) ft = 66.67 ft³ = 66.67 ÷ 27 = 2.469 yd³
- With 5% waste: 2.469 × 1.05 = 2.59 yd³ (1.98 m³)
- Weight = 1.9822 m³ × 1,690 kg/m³ = 3,350 kg = 3.69 short tons (3.35 tonnes)
These are the same numbers the calculator shows when it first loads.
Method and formulas
Rectangle: A = L × W · Circle: A = π × D² ÷ 4 · Triangle: A = B × H ÷ 2
V = A × d × f × (1 + w ÷ 100)
Weight = V × ρ
1 yd³ = 0.764554857984 m³ · 1 short ton = 2,000 lb · 1 tonne = 1,000 kg
- A
- Plan area of the gravel layer
- d
- Depth of the layer
- f
- Loose-to-compacted factor (1 for a loose layer)
- w
- Waste allowance, %
- ρ
- Loose bulk density of the product, as delivered
Assumptions and limits
- Uniform depth over the whole area.
- Density is the loose (as-delivered) bulk density of the product ordered.
- Density varies by rock type, grading and moisture; the default is the handbook loose weight for dry 1/4 in to 2 in gravel, not a property of all gravel.
- Does not design a pavement or base course thickness.
Reference tables
| Material | Loose kg/m³ | Loose lb/yd³ |
|---|---|---|
| Gravel — Pitrun | 1,930 | 3,250 |
| Gravel — Dry | 1,510 | 2,550 |
| Gravel — Dry 6-50 mm (1/4"-2") | 1,690 | 2,850 |
| Gravel — Wet 6-50 mm (1/4"-2") | 2,020 | 3,400 |
| Sand & gravel — Dry | 1,720 | 2,900 |
| Sand & gravel — Wet | 2,020 | 3,400 |
| Stone — Crushed | 1,600 | 2,700 |
Source: Caterpillar Performance Handbook, Edition 50 (AEXQ3330), Tables section, "Weight of Materials", page 27-6 (loose weights).
Values as printed in the handbook, which adds: “Varies with moisture content, grain size, degree of compaction, etc. Tests must be made to determine exact material characteristics.” The calculator uses the kg/m³ figure; the handbook rounds the lb/yd³ column separately.
Coverage
| Depth | Area covered by 1 yd³ |
|---|---|
| 1 in | 324.0 ft² |
| 2 in | 162.0 ft² |
| 3 in | 108.0 ft² |
| 4 in | 81.0 ft² |
| 5 in | 64.8 ft² |
| 6 in | 54.0 ft² |
Source: Calculated with the EngiFormula gravel engine (method v2.0). Unit conversion uses the exact definitions 1 in = 25.4 mm, 1 ft = 0.3048 m and 1 yd = 0.9144 m, NIST Special Publication 811 (2008 edition), Appendix B.
Metric
| Depth | Area covered by 1 m³ |
|---|---|
| 2.5 cm | 40.00 m² |
| 5 cm | 20.00 m² |
| 7.5 cm | 13.33 m² |
| 10 cm | 10.00 m² |
| 12.5 cm | 8.00 m² |
| 15 cm | 6.67 m² |
Source: Calculated with the EngiFormula gravel engine (method v2.0). Unit conversion uses the exact definitions 1 in = 25.4 mm, 1 ft = 0.3048 m and 1 yd = 0.9144 m, NIST Special Publication 811 (2008 edition), Appendix B.
Common uses
- Driveway top-up: enter the driveway size and the depth you are adding.
- Pea gravel patio or path: use the supplier's density for pea gravel.
- French drain trench: use the trench length and width, and the gravel depth in the trench.
Frequently asked questions
How do I calculate how much gravel I need for an area?
Multiply the length by the width to get the area, multiply by the depth (in feet, or metres) to get the volume, then add a waste allowance. Divide cubic feet by 27 for cubic yards. A 20 × 10 ft area at 4 in deep with 5% waste needs 2.59 yd³.
How much will 1 ton of gravel cover?
It depends on the depth and the density. At 1,690 kg/m³ (105.5 lb/ft³), the handbook figure for dry 1/4 in to 2 in gravel, one short ton covers about 114 ft² at 2 in deep and about 57 ft² at 4 in deep. Enter your supplier's density in the calculator for your gravel.
How much gravel do I need for a 10x10 area?
At 4 in deep with 5% waste, a 10 × 10 ft area needs 1.30 yd³, or about 1.85 short tons at the default density of 1,690 kg/m³. Change the depth in the calculator for a different thickness.
How many tons of gravel do I need?
Work out the volume (area × depth), add a waste allowance, then multiply by the density. For a 20 × 10 ft area at 4 in deep with 5% waste, that is 2.59 yd³, or about 3.69 short tons at the default density of 1,690 kg/m³.
What is the difference between cubic yards and tons?
Cubic yards measure volume (how much space the gravel fills); tons measure weight. You convert between them with the density: weight = volume × density.
How much does a cubic yard of gravel weigh?
It depends on the product. The Caterpillar Performance Handbook (Edition 50) lists loose weights from 2,550 lb per cubic yard for dry gravel to 3,250 lb for pit-run gravel; see the table on this page. At 1,690 kg/m³ (105.5 lb/ft³), the handbook figure for dry 1/4 in to 2 in gravel, one cubic yard weighs 1.42 short tons. Your supplier can give you the figure for the exact gravel you are buying.
How deep should driveway gravel be?
The right depth depends on the ground, the traffic and the gravel used, so follow your local practice or your supplier's advice. This calculator works out quantities for whatever depth you choose; it does not design a driveway.
Sources and references
- NIST Special Publication 811, Guide for the Use of the International System of Units (SI), 2008 edition, Appendix B (exact values for the inch, foot, yard and pound).
- Caterpillar Inc., Caterpillar Performance Handbook, Edition 50 (AEXQ3330), Tables section, “Weight of Materials”, page 27-6.
- Area and volume relations: plane geometry, as set out in the Method section above.
About this calculator
Scope and disclaimer
Estimates volume and weight of loose aggregate for ordering. Not a pavement design. Density varies by rock type, grading and moisture, so the weight is only as good as the density you enter.
This calculator gives information and preliminary estimates only. It is not professional design advice and does not replace the governing code, product instructions or a qualified professional's judgement for your project.