How to measure for gravel
Measure the length and width of rectangular areas in feet, or the diameter of a circular area. Then enter the planned gravel depth. For US units, depth is entered in inches because most homeowners think about gravel layers that way.
If the area is irregular, split it into smaller rectangles or circles, calculate each section, and add the quantities together.
How the calculation works
The calculator first finds area, then multiplies by depth to get volume. It converts that volume into cubic feet, cubic yards, and cubic meters. Weight is estimated from the selected material density.
Circle area = pi x (diameter / 2)^2
Volume = area x depth
Weight = volume x estimated density
Order amount = net amount x (1 + waste allowance)
Worked example
Suppose you need gravel for a 20 ft by 10 ft area at 4 inches deep. The net volume is about 66.7 cubic feet, or 2.47 cubic yards. Using a 100 lb/ft3 density, the estimated weight is about 3.33 US tons. With a 10% allowance, the recommended order is about 3.7 tons. At $42 per ton, the material estimate is about $155.
Interpreting the result
Use the net amount to understand the physical volume of the space. Use the waste-adjusted quantity when ordering, because real projects often lose material to uneven depth, compaction, delivery spread, edging gaps, and small measurement errors.
Assumptions
- US tons are short tons of 2,000 pounds.
- Depth is treated as an even finished layer.
- Compaction and moisture can change final coverage.
- Supplier density should override these presets when available.
Gravel density presets
Density values are centralized estimates used for planning. Actual bulk density varies by local stone, gradation, moisture, and how the material is loaded or compacted.
| Material | Density | Note |
|---|---|---|
| General gravel | 100 lb/ft3 | A broad planning estimate for mixed gravel. |
| Pea gravel | 105 lb/ft3 | Small rounded gravel commonly used for paths and drainage. |
| Crushed stone | 100 lb/ft3 | Angular crushed aggregate; density varies by stone type and gradation. |
| River rock | 110 lb/ft3 | Rounded decorative stone that can be heavier per cubic foot. |
| Limestone | 95 lb/ft3 | Common driveway and base aggregate; verify local supplier weight. |
| Road base | 120 lb/ft3 | Dense graded aggregate used for compacted base layers. |
| Decorative gravel | 100 lb/ft3 | Planning estimate for decorative landscape gravel. |
Practical homeowner guidance
- Round up before ordering, especially for small projects.
- Ask the supplier whether their price is per ton, cubic yard, or bag.
- For driveways, confirm the base design and compaction needs before ordering.
- For decorative areas, use edging to help keep the finished depth consistent.
FAQs
How deep should gravel be?
For many landscape beds and paths, 2 to 4 inches is common. Driveways and compacted base layers may need more depth and should follow project-specific guidance.
Should I order gravel by cubic yards or tons?
Many landscape suppliers sell bulk gravel by the ton, while project measurements are often easier in cubic yards. This calculator shows both so you can compare against supplier pricing.
Why does gravel weight vary?
Stone type, particle size, moisture, compaction, and the amount of void space between stones all affect density. Use a supplier density when a precise order matters.
Is this calculator suitable for structural design?
No. It is a homeowner planning estimate for material quantity and cost. Structural, drainage, driveway, and code-sensitive work may need professional review.
References
Unit conversions follow standard published conversion factors from NIST conversion factor guidance.