How to Use Gravel Calculator
The Gravel Calculator helps you estimate the exact amount of gravel required for any landscaping or construction project. Whether you are planning a driveway, garden path, or drainage layer, the Gravel Calculator removes the guesswork from material procurement.
- Enter dimensions — Input the Length, Width, and Depth (thickness) of the area to be covered.
- Select a unit — Choose m, cm, ft, or in to match your site measurements.
- Choose gravel type — Select a preset material or enter a custom density in kg/m³.
- Set wastage allowance — Enter a percentage (default 5%) to account for spillage and uneven surfaces.
- Read results — The Gravel Calculator shows net volume, volume with wastage, and estimated weight in metric tonnes.
The Gravel Calculator updates all values instantly as you adjust any input.
Formula & Theory — Gravel Calculator
The Gravel Calculator applies the following formulas:
Volume (m³) = Length × Width × Depth
Volume with wastage (m³) = Volume × (1 + wastage% / 100)
Weight (kg) = Volume with wastage × Density (kg/m³)
| Symbol | Meaning |
|---|---|
| L, W, D | Length, width, and depth (converted to metres) |
| ρ | Gravel density in kg/m³ |
| w | Wastage percentage (e.g., 5 for 5%) |
Typical Gravel Densities
The Gravel Calculator uses these reference densities:
| Gravel Type | Density (kg/m³) |
|---|---|
| Pea Gravel | 1,680 |
| Crushed Stone | 1,600 |
| River Gravel | 1,650 |
| Decomposed Granite | 1,780 |
| Lava Rock | 900 |
| Sand | 1,600 |
Actual bulk density can vary by moisture content and particle size. For precise projects, use the Gravel Calculator's custom density field with values from your supplier's data sheet.
Use Cases for Gravel Calculator
The Gravel Calculator is invaluable for homeowners, landscapers, and construction teams:
- Driveways — Calculate how much crushed stone or pea gravel is needed to cover a driveway to the recommended 10–15 cm depth.
- Garden paths — Use the Gravel Calculator to order the right amount of decorative river gravel or lava rock for garden walkways.
- Drainage layers — Estimate gravel volume for French drains, soakaways, or foundation drainage beds to ensure adequate water dispersal.
- Playgrounds & patios — Plan pea gravel coverage for soft-fall zones or patio bases with accurate weight estimates for delivery planning.
- Erosion control — Size riprap or crushed stone quantities for slope stabilisation and erosion prevention using the Gravel Calculator.
Whether your project is measured in square metres or square feet, the Gravel Calculator converts units automatically and delivers reliable volume and weight estimates.