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Gravel Calculator: Volume and Weight
Work out how much gravel, crushed stone or sand a driveway, path or drainage trench needs. Enter the size and the density your supplier quotes to get volume and weight in tons or tonnes.
Volume first, then weight
Aggregates are priced by weight in many places and by volume in others, so the calculator gives both. First it finds the finished volume as length × width × depth, adds the compaction allowance, and then multiplies by the bulk density: weight = volume × density.
Density here is the bulk density of the loose material, including the gaps between stones, not the density of solid rock. Solid rock is much heavier than the loose pile you actually buy.
Choosing a depth
Depth depends on the job. A decorative path needs only a thin layer, while a driveway or a base under pavers needs a thicker, compacted layer, often built in stages with different stone sizes. The right figure depends on vehicle loads, soil and local practice, so treat any depth you enter as a plan to confirm with the supplier or an installer.
If the ground is soft or drains poorly, extra depth or a geotextile layer is often discussed by installers. Neither is something this calculator can judge.
Typical density ranges
| Material | Rough bulk density |
|---|---|
| Dry sand | about 1,400 to 1,600 kg/m³ |
| Crushed stone or gravel | about 1,400 to 1,700 kg/m³ |
| Wet sand or damp gravel | can be 10 to 20% heavier |
These are broad ranges. Moisture content, grading and the type of rock all change the real figure, so use your supplier's number when you have it.
Ordering tips
- Measure irregular areas by splitting them into rectangles and add the weights.
- Ask whether the quoted tons are US short tons (2,000 lb), long tons or metric tonnes (1,000 kg). The three differ by up to about 12%.
- Delivered loads are often rounded to the truck size, so check the minimum.
Ordering and delivery tips
Suppliers sell gravel by weight (tonnes or tons) or by volume (cubic metres or yards), so confirm which unit a quote uses before comparing prices. Loose material settles once it is spread and compacted, so many installers add a compaction allowance, often somewhere around 10% to 20% depending on the material. Moisture changes weight: wet gravel is heavier per cubic metre than dry gravel, so a load sold by weight may cover less volume when wet. Check access for the delivery truck and any minimum load size before you order.
Worked example
A 30 ft by 12 ft parking pad covered with 4 inches of crushed stone, using a density of 1,600 kg/m³ and a 15% compaction allowance.
Inputs
| Units | Imperial (feet and inches) |
|---|---|
| Length (feet or meters) | 30 |
| Width (feet or meters) | 12 |
| Depth (inches or centimeters) | 4 |
| Material density | 1600 kg/m³ |
| Compaction and waste allowance | 15 % |
Result
To order: 5.11 cubic yards, or 3.91 cubic meters, including the allowance.
| Finished volume | 3.398 m³ (4.444 yd³) |
|---|---|
| Volume to order | 3.908 m³ (5.111 yd³) |
| Weight in kilograms | 6,252 kg |
| Weight in pounds | 13,784 lb |
Estimating note: Quantities and ratings here are estimates for planning and learning. Products, local codes and site conditions differ, so check manufacturer data and local regulations, and use a qualified professional for electrical, structural or safety-critical work.
Frequently asked questions
How many tons of gravel do I need for a driveway?
Multiply the area by the depth to get the volume, add a compaction allowance, then multiply by the density. A 30 by 12 foot drive at 4 inches deep needs around 3 to 3.5 US tons at typical densities.
How do I convert cubic yards of gravel to tons?
Multiply cubic yards by the density in tons per cubic yard. With a bulk density near 1,600 kg/m³ one cubic yard weighs about 1.2 metric tonnes, or roughly 1.35 US tons.
What density should I use for gravel?
Use the number your supplier gives for the product. If you do not have one, a figure between 1,400 and 1,700 kg/m³ is a common planning range for loose crushed stone.
Why include a compaction allowance?
Loose stone packs down once it is spread and compacted, so the finished layer is thinner than the loose pile. Adding a percentage keeps you from coming up short.
Can I use this calculator for sand or topsoil?
Yes, as long as you enter a realistic bulk density for that material. Wet material is noticeably heavier than dry, so check the moisture condition when it is delivered.
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References and sources
- Supplier safety data sheets and product data sheets give bulk density for specific aggregates.