Gravel Calculator Guide
How Much Gravel Do I Need?
Learn how to estimate gravel for driveways, patios, walkways, landscaping, drainage, and concrete base layers using length, width, depth, cubic yards, tons, and waste allowance.
Gravel calculation formula
To calculate how much gravel you need, measure the project length, width, and planned gravel depth. Convert the depth into feet if you are using inches. Then multiply length by width by depth to get cubic feet.
Step 1
Length × Width × Depth = Cubic Feet
Step 2
Cubic Feet ÷ 27 = Cubic Yards
Step 3
Cubic Yards × Tons Per Cubic Yard = Estimated Tons
Common gravel depths
Example gravel estimate
For a 20-foot by 10-foot area with 4 inches of gravel, convert 4 inches to 0.33 feet. The volume is about 66.67 cubic feet. Divide by 27 to get about 2.47 cubic yards. At 1.4 tons per cubic yard, that equals about 3.46 tons before waste.
Length
20 ft
Width
10 ft
Depth
4 in
Estimated gravel
3.46 tons
Gravel projects this works for
The same basic gravel formula works for many construction, landscaping, and drainage projects. The main variable is depth, because driveway gravel, patio base, decorative gravel, and drainage gravel often require different material thicknesses.
- • Driveways
- • Patios and paver bases
- • Walkways and paths
- • Concrete slab base layers
- • Drainage trenches and French drains
- • Decorative landscaping beds
- • Gravel pads for sheds, equipment, and small structures
What affects how much gravel you need?
Gravel estimates can change depending on material type, depth, compaction, soil condition, drainage needs, slope, and waste allowance. For larger projects, confirm final quantities with a local supplier or contractor.
- • Project length and width
- • Gravel depth
- • Gravel type and density
- • Compaction
- • Uneven ground
- • Delivery and spreading loss
- • Whether the area needs a base and top layer
Related gravel tools
How much gravel do I need FAQ
How do I calculate how much gravel I need?
Multiply length by width by depth to calculate gravel volume. Convert depth from inches to feet when using imperial units. Then divide cubic feet by 27 to get cubic yards.
How many tons of gravel do I need?
After calculating cubic yards, multiply cubic yards by the gravel density. A common planning estimate is 1.4 tons per cubic yard, but actual weight varies by material type, moisture, and supplier.
How deep should gravel be?
Decorative gravel may need 2 to 3 inches, walkways often use 2 to 4 inches, concrete base layers often use 4 to 6 inches, and driveways may use 4 to 12 inches depending on load and soil.
Should I add waste to my gravel estimate?
Yes. Add 5% to 10% extra gravel for spreading, compaction, uneven ground, and material loss.