Gravel Calculator
This gravel calculator turns the size and depth of your project into cubic yards, short tons and bags. Pick a rectangle, a circle or an area you already know, choose pea gravel, crushed stone, river rock, sand or topsoil, and see how much to order in bulk or by the bag. The weight uses a typical density you can replace with your supplier's figure.
Updated
Results
- Volume (cu ft)
- Weight (lb)
- Bags (count)Rounded up to whole bags of the type chosen
- Area (sq ft)
- Density used (lb/yd³)Material default or your custom value
- Cost buying by the tonShown when you enter a price per ton
- Cost buying by the cubic yardShown when you enter a price per cubic yard
- Cost buying bagsShown when you enter a price per bag
Results are estimates. See the methodology below.
How to use the gravel calculator
- Choose the shape: Rectangle (length × width), Circle (diameter) or Known area if you already have the square footage. Split an L-shaped patio into two rectangles and add the results.
- Enter the finished depth in inches. Measure the depth you want after spreading, not the depth of the hole.
- Pick the material. Each one comes with a typical loose, dry weight per cubic yard.
- Choose the bag type: 0.5 cu ft bags are counted by volume, 50 lb bags by weight.
- Open Advanced options to type the weight per cubic yard your quarry or yard quotes, or to add an extra percentage for compaction and spillage.
- Add a price per ton, per cubic yard or per bag if you want a cost line for each way of buying.
How the calculator works
- Area = length × width, or π × (diameter ÷ 2)² for a circle
- Cubic feet = area × depth ÷ 12 × (1 + extra %)
- Cubic yards = cubic feet ÷ 27
- Pounds = cubic yards × density; tons = pounds ÷ 2,000 (US short tons)
- Bags = cubic feet ÷ 0.5, or pounds ÷ 50, rounded up
Typical densities you can change
The defaults are estimates for loose, dry material. Real weight depends on the quarry, the size grading and how wet the load is, so treat them as starting points:
| Material | Default (lb/yd³) | Tons per cubic yard |
|---|---|---|
| Pea gravel | 2,835 | 1.42 |
| Crushed stone | 2,500 | 1.25 |
| River rock | 2,835 | 1.42 |
| Sand | 2,619 | 1.31 |
| Topsoil | 2,160 | 1.08 |
Pea gravel and river rock use Engineering ToolBox's figure for dry gravel (105 lb/ft³); river rock sharing that value is an assumption. Sand uses dry sand (97 lb/ft³) and topsoil uses loam (80 lb/ft³). Crushed stone sits in the middle of the 2,410–2,590 lb/yd³ range a Missouri DOT conversion table gives for loose granite or limestone. If your supplier sells by the ton and quotes a weight per yard, enter it in the custom density field.
Worked examples
Patio base, 20 × 10 ft at 3 in
With crushed stone the area is 200 sq ft and the volume 50.0 cu ft, which is 1.85 cubic yards or about 2.31 tons (4,630 lb). Bagged, that is 100 bags of 0.5 cu ft or 93 bags of 50 lb.
Garden path, 40 × 3 ft at 2 in of pea gravel
120 sq ft gives 20.0 cu ft, 0.74 cubic yards and 1.05 tons. You would need 40 half-cubic-foot bags or 42 bags of 50 lb.
Parking pad, 50 × 12 ft at 4 in, plus 10 %
Crushed stone with a 10 % allowance comes to 220.0 cu ft, 8.15 cubic yards and 10.19 tons. If the quarry says its stone weighs 2,700 lb per yard, enter that and the weight rises to 11.00 tons for the same volume.
Quick rule
One cubic yard covers 324 sq ft at 1 in deep, or 108 sq ft at 3 in.
Bulk or bags, yards or tons
Landscape yards often sell by the cubic yard, quarries by the ton; the calculator shows both so you can compare quotes. Suppliers may have a minimum order or sell in set increments, and many charge for delivery; none of that is included. Sloped ground, a geotextile fabric layer or several base layers of different stone are not modeled: run each layer separately with its own depth. For the slab or footing that goes on top, use our concrete calculator; for bark or wood-chip beds, our mulch calculator.
Frequently asked questions
How many tons are in a cubic yard of gravel?
It depends on the stone. With the defaults, a cubic yard is 1.25 tons of crushed stone and 1.42 tons of pea gravel. Ask your supplier for its weight per yard and type it in for a closer figure.
How much area does a ton of gravel cover?
At 3 in deep, one ton of crushed stone (0.80 cubic yards at the default density) covers about 86.4 sq ft, and a full cubic yard (1.25 tons) covers 108 sq ft. A thinner layer covers more; a deeper one, less. Heavier stone covers less per ton.
How deep should gravel be?
Decorative paths are often laid 2 to 3 in deep, while driveways are usually built deeper in compacted layers of different stone. Follow your project plan or your supplier's advice; the calculator handles any depth from ¼ in up.
Should I order extra for compaction?
Compacted stone takes up less room than loose stone, so many people order a little more. Use the extra percentage field to add your own allowance instead of guessing at the final number.
Is it cheaper to buy gravel in bags or in bulk?
Enter both prices and compare the cost lines. Bags are handy for small jobs; for anything near a cubic yard, check bulk prices and delivery fees in your area.
Can I use it for sand or topsoil?
Yes. Pick sand or topsoil from the material list. Moist topsoil and wet sand weigh more than the dry defaults, so use the custom density if your supplier gives one.
Sources
- Engineering ToolBox — Dirt and Mud densities (gravel dry 105, sand dry 97, loam 80 lb/ft³)
- Missouri DOT server — Highway Maintenance Tables and Conversion Factors (loose granite/limestone 2,410–2,590 lb/yd³; PDF without publisher line)
- NIST — Approximate conversions from U.S. customary measures to metric (short ton = 2,000 lb, cubic yard)
This is a material estimate based on typical densities and the dimensions you enter. Confirm weights, minimum orders and delivery with your supplier before ordering.