How much gravel do I need?
Measure the coverage area in square feet, enter depth in inches, and convert the volume to cubic yards. A 300 sq ft area at 3 inches deep is about 2.78 cubic yards before waste.
Cubic yards vs tons
The calculator can estimate volume in cubic yards, but many suppliers sell gravel or rock by the ton. Use supplier density to convert between volume and weight when ordering.
Depth, compaction, and waste
Decorative rock, paths, driveways, and base layers use different depths. Compacted base material may need more loose material than the finished compacted depth suggests.
When to calculate sections separately
Calculate separate sections when the project has different depths, such as a compacted base layer plus a decorative top layer.
Gravel project example estimates
Examples are before waste and before any tonnage conversion. Supplier density and compaction can change the order.
| Project example | Area and depth | Cubic yards |
|---|---|---|
| Path | 150 sq ft at 2 in | 0.93 cu yd |
| Decorative rock bed | 250 sq ft at 3 in | 2.31 cu yd |
| Small parking pad | 300 sq ft at 4 in | 3.70 cu yd |
| Driveway strip | 480 sq ft at 4 in | 5.93 cu yd |
| Deep base layer | 600 sq ft at 6 in | 11.11 cu yd |
Gravel coverage by depth
Coverage assumes 1 cubic yard, which is 27 cubic feet. Waste, compaction, settling, and irregular grade are not included.
| Depth | Coverage from 1 cu yd | Coverage from 2 cu yd |
|---|---|---|
| 1 in | 324 sq ft | 648 sq ft |
| 2 in | 162 sq ft | 324 sq ft |
| 3 in | 108 sq ft | 216 sq ft |
| 4 in | 81 sq ft | 162 sq ft |
| 6 in | 54 sq ft | 108 sq ft |
| 12 in | 27 sq ft | 54 sq ft |
Before you calculate
- Measure drain length, width, and rock depth separately from decorative landscape areas.
- Keep pipe, fabric, basin, outlet, and cover-depth details visible as separate planning items.
- Calculate separate drain runs when width, depth, pipe detail, or aggregate type changes.
Common mistakes
- Treating a drainage trench like a shallow decorative rock bed.
- Ordering decorative rock without confirming drainage-suitable aggregate.
- Forgetting that trench shape, pipe, fabric, and uneven bottoms can change real usage.
Formula
cubic yards = (area * (depth / 12) / 27) * (1 + wastePercent / 100)
Assumptions
- Depth, compaction, moisture, product size, and delivery minimums can change final quantity.
- Measure each pad, bench zone, kiosk base, and walkway section separately when material or depth changes.
- Round up to full bags, rolls, cubic yards, tons, or delivery minimums before ordering.
Example
Estimated stormwater garage corner sump discharge splash pad gravel pad needed (cubic yards): 1.16 cubic yards
How to calculate stormwater garage corner sump discharge splash pad gravel pad cubic yards
- Measure the target coverage area in square feet.
- Enter the planned finished depth in inches.
- Convert depth to feet, multiply by area, then divide cubic feet by 27 to get cubic yards.
- Add waste for uneven grade, compaction, spreading loss, or ordering increments.
- Confirm supplier units before buying, because bulk material may be sold by cubic yard, ton, or bag.
Before you buy materials
- Confirm aggregate size and drainage suitability with the supplier or project specification.
- Round up for trench irregularity, placement loss, and delivery units.
FAQ
What is the example stormwater garage corner sump discharge splash pad gravel pad cubic-yard result?
Use area, installed depth, cubic-foot to cubic-yard conversion, and waste, then calculate the planning result. In the default example, the result is 1.16 cubic yards.
How do I calculate gravel cubic yards?
Use cubic yards = area x (depth inches / 12) / 27, then add waste if needed.
How many square feet does 1 cubic yard of gravel cover?
One cubic yard covers about 162 sq ft at 2 inches deep, 108 sq ft at 3 inches, 81 sq ft at 4 inches, or 54 sq ft at 6 inches before waste.
Should I order gravel by yards or tons?
Use the unit your supplier sells. Cubic yards estimate volume, while tons estimate weight. Density connects the two.
Should I include compaction?
Yes for base layers and driveways. Compaction, subgrade variation, and delivery loss are common reasons to include waste.
Does this replace a site estimate?
No. It is a planning calculator. Final quantity depends on grade, base condition, material type, and supplier delivery units.
Related calculators
This calculator is for planning estimates only. Verify final quantities with product labels, project conditions, and a qualified professional when accuracy matters.