Gravel Calculator
Bag count is rounded up so you buy whole bags. Results are estimates, since actual gravel density varies by supplier.
Use this free gravel calculator to find out exactly how much gravel your project needs. Enter the length and width of the area, the depth you plan to spread, and your material type, and it instantly shows the volume in cubic feet and cubic yards, the weight in tons, and how many 50 lb bags to buy.
How the Gravel Calculator Works
A gravel calculator converts the size of a rectangular area into a volume, then into a weight you can actually order. First it turns the depth in inches into feet, then it multiplies length times width times depth to get cubic feet. Dividing by 27 gives cubic yards. Finally, multiplying cubic yards by the material density gives tons.
Pea gravel is smooth, rounded stone often used for paths, patios, and play areas, weighing about 1.35 tons per cubic yard. Crusher run is angular crushed stone mixed with fine dust that packs down hard for driveways, at about 1.60 tons per cubic yard.
How to Use the Gravel Calculator
- Measure the length and width of the area in feet. For a curved path, break it into smaller rectangles and add the results together.
- Choose your depth in inches. A garden path usually needs 2 to 3 inches, while a driveway for cars needs 4 to 6 inches over a compacted base.
- Pick your material. Select pea gravel for decorative areas or crusher run for a firm, drivable surface.
- Set your waste allowance. The default of 10 percent covers most jobs, but use 5 percent on flat, even ground and up to 15 percent on rough or sloped ground.
- Click Calculate Gravel and read off the cubic feet, cubic yards, tons, and bag count. Order by cubic yards for bulk delivery or by bags for small jobs.
Gravel Depth Guide
Depth matters more than most people expect, because doubling the depth doubles the gravel you need. A thin layer shifts underfoot and exposes the ground, while an overly thick layer wastes money. The table below gives sensible starting points for common projects.
| Project type | Recommended depth | Notes |
|---|---|---|
| Garden path | 2 to 3 inches | Use edging to keep gravel in place |
| Patio or seating area | 3 to 4 inches | Compact the base before spreading |
| Driveway (cars) | 4 to 6 inches | Crusher run packs down best |
| Parking pad (trucks) | 6 to 8 inches | Consider a deeper compacted base layer |
If your project sits next to a hard surface, remember that gravel spreads differently than a solid slab. When you are also planning a poured surface, a concrete volume estimator can help you compare the two options. For planting beds next to a gravel path, a mulch quantity tool works the same way, using area and depth to find the volume you need.
Verified Gravel Calculator Examples
The table below shows real results from this calculator, so you can check your numbers against a known answer before you order.
| Area | Depth | Material | Waste | Result |
|---|---|---|---|---|
| 10 x 20 ft | 3 in | Pea gravel | 0% | 50 cu ft, 1.85 cu yd, 2.50 tons, 100 bags |
| 10 x 20 ft | 3 in | Pea gravel | 10% | 55 cu ft, 2.04 cu yd, 2.75 tons, 110 bags |
| 12 x 24 ft driveway | 4 in | Crusher run | 0% | 96 cu ft, 3.56 cu yd, 5.69 tons |
Notice how the 10 percent waste allowance on the 10 by 20 foot area adds exactly 5 cubic feet, taking the total from 50 to 55 cubic feet and the bag count from 100 to 110. That small buffer is often the difference between finishing the job and making a second trip to the store. If your project also includes painted surfaces, a paint coverage estimator can tell you how much paint that part needs, and for garden beds you can pair this result with a topsoil volume calculator to work out the soil underneath.
How Many Tons of Gravel Do I Need?
Suppliers usually sell gravel by the ton or by the cubic yard, so it helps to know both numbers. A cubic yard of pea gravel weighs about 1.35 tons, while a cubic yard of crusher run weighs about 1.60 tons. A typical two-car driveway needs roughly 5 to 10 tons, while small garden paths often need less than 1 ton. Buying bags makes sense up to about 1 ton, after which bulk delivery is usually cheaper per ton. Always confirm the density with your supplier before a large order, since moisture and stone size shift the weight slightly.
Frequently Asked Questions About Gravel
How much gravel do I need for a driveway?
Measure the driveway in feet, then choose 4 to 6 inches deep for car traffic. A 12 by 24 foot driveway at 4 inches deep needs 3.56 cubic yards, or 5.69 tons of crusher run. Add a 10 percent waste allowance for uneven ground.
How many bags of gravel make a cubic yard?
One cubic yard of pea gravel weighs about 1.35 tons, which is 2,700 pounds, or 54 bags of 50 pounds each. For crusher run at 1.60 tons per cubic yard, one cubic yard equals 64 bags. This calculator rounds the bag count up, so you never come up short.
How deep should gravel be for a path?
A garden path needs 2 to 3 inches of gravel over a compacted base. Less shifts easily and exposes the ground, while more feels loose underfoot.
What is the difference between pea gravel and crusher run?
Pea gravel is smooth, rounded stone that looks decorative but moves underfoot and does not compact well. Crusher run is angular crushed stone with fine dust that locks together when compacted, making it the better choice for driveways and parking areas.
How do I calculate gravel for a round area?
For a circle, measure the radius in feet, multiply 3.14 times the radius squared to get the area, then multiply by the depth in feet and divide by 27 for cubic yards. Or measure the enclosing square and reduce the result by about 20 percent.
Should I order gravel by the ton or by the cubic yard?
Order by whichever unit your supplier quotes, since both describe the same load. Bulk orders are usually priced per ton, while bagged gravel is priced per bag. Use the tonnage from this calculator for bulk delivery and the bag count for store purchases.
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