Gravel Calculator
Estimate gravel for a driveway, drainage trench, shed base, or decorative bed — in cubic yards, tons, and bags.
How to calculate gravel
Gravel is sold by volume or weight. Measure the area in feet, convert the depth from inches to feet, then divide by 27 for cubic yards. Multiply by about 1.4 to estimate tons.
Length × width × (depth ÷ 12) = cubic feet. Cubic feet ÷ 27 = cubic yards. Cubic yards × 1.4 = tons (planning estimate).
Example: 20 × 10 ft at 2 inches deep is 33.3 cubic feet, or 1.23 cubic yards. With 10% waste, that is about 1.36 cubic yards, 1.9 tons, or 74 bags of 0.5 cu ft gravel.
Gravel coverage chart
| Depth | 1 cubic yard covers | 1 ton covers |
|---|---|---|
| 1 in | 324 sq ft | 231 sq ft |
| 2 in | 162 sq ft | 116 sq ft |
| 3 in | 108 sq ft | 77 sq ft |
| 4 in | 81 sq ft | 58 sq ft |
Based on 1.4 tons per cubic yard. Add 10–20% for compaction, uneven subgrade, and settling.
Common gravel types
| Type | Best for | Notes |
|---|---|---|
| #57 crushed stone | Drainage, driveways, decorative beds | Clean stone; drains well but moves under tires |
| #411 | Base under pavers, concrete, and sheds | Mixed with fines; compacts firm |
| Pea gravel | Play areas, paths, decorative beds | Smooth and round; can migrate |
| River rock | Dry creeks, borders, low-traffic beds | Larger and more expensive |
| Crushed stone dust | Paver bedding, tight bases | Compacts; not for drainage |
How deep should gravel be?
- Decorative beds: 2–3 inches over landscape fabric.
- Driveway: 4–6 inches of compacted base, plus a top layer.
- Shed base: 2–4 inches of compacted #411 over a geotextile.
- Drainage: 2–4 inches, or a trench filled with clean stone.
- Paver base: 4–6 inches, compacted in 2-inch lifts.
Compaction and waste
Loose gravel settles by roughly 10–20% after compaction. Order on the high side for driveways and bases, and compact in thin lifts. For decorative beds, a 10% allowance is usually enough.
Bulk vs. bags
| Bulk gravel | 0.5 cu ft bags | |
|---|---|---|
| Typical price | $45–$65 per cubic yard | $5.00–$7.00 per bag |
| 100 sq ft at 2 in | About $35–$55 | About $180–$260 |
| Best for | Driveways, drainage, large beds | Small patches, pots, tight access |
| Watch for | Delivery, minimum loads, access | Cost per cubic yard, bag weight |
For anything larger than a small bed, bulk is the better buy. Bags are useful when you need a few cubic feet or cannot get a truck close to the work area.
Before you order
- Decide whether you need clean stone (#57) or a compactable base (#411).
- Measure the area and add 10–20% for compaction.
- Ask for the weight per yard; it varies by stone type and moisture.
- Plan delivery access and a stable spot for the pile.
- Use a geotextile under decorative gravel to slow weeds and migration.
Frequently asked questions
How many tons of gravel are in a cubic yard?
Most gravel weighs about 1.35 to 1.45 tons per cubic yard. The calculator uses 1.4 tons per yard. Moisture, stone size, and compaction change the number, so ask the supplier for the exact weight.
How much gravel do I need for 100 square feet?
At 2 inches deep, 100 square feet needs 16.7 cubic feet, or about 0.62 cubic yards. With 10% waste, that is about 0.68 cubic yards or 0.95 tons. At 4 inches, double it.
What is the difference between #57 and #411 gravel?
#57 is a clean, open-graded stone that drains well; it is common for drainage, driveways, and decorative beds. #411 is a mixed stone with fines that compacts into a firm base; it is better under pavers and concrete.
How deep should gravel be for a driveway?
A gravel driveway usually needs 4 to 6 inches of compacted base, plus a top layer. Soft or wet subgrade may need more. Build in lifts and compact each one; loose gravel will rut.
Are bags or bulk gravel cheaper?
Bulk is cheaper once you need about 1 cubic yard or more. Bags are convenient for small beds, drainage spots, and sites a truck cannot reach, but the cost per cubic yard is much higher.