Gravel Calculator
Calculate how much gravel you need for a driveway, pathway, or drainage project — in cubic yards, cubic feet, US tons, and metric tonnes. Includes a 10% compaction allowance.
Gravel Calculator form
Result
How this calculator works
The calculator multiplies length × width × depth (converted from inches to feet) to get the volume in cubic feet, then converts to cubic yards and cubic meters. Mass is calculated using a standard gravel density of 2,835 lb per cubic yard (typical for crushed stone and pea gravel).
The recommended order adds a 10% allowance for compaction and settling — gravel compacts significantly after the first rain or after tamping, so ordering the exact volume almost always leaves you short.
Formula
volume_cuft = length × width × (depth / 12)
volume_cuyd = volume_cuft / 27
lbs = volume_cuyd × 2835
us_tons = lbs / 2000
tonnes = lbs / 2204.62
recommended = us_tons × 1.10 (10% compaction allowance)
Example
For a 10 ft × 10 ft driveway base at 4 inches deep:
- volume_cuft = 10 × 10 × (4/12) = 33.33 cu ft
- volume_cuyd = 33.33 / 27 ≈ 1.234 cu yd
- lbs = 1.234 × 2835 ≈ 3,500 lb
- us_tons ≈ 1.75 tons
- recommended order ≈ 1.93 tons (with 10% compaction)
Important assumptions
- Density assumption: 2,835 lb per cubic yard (crushed stone / pea gravel at standard compaction).
- Pea gravel runs slightly lighter (~2,700 lb/yd³); crushed limestone runs slightly heavier (~2,960 lb/yd³).
- Depth should be the compacted depth you want to end up with, not the loose depth. Loose gravel compacts by ~20%.
- Always order 10% extra for compaction, uneven subgrade, and spillage.
FAQ
- How deep should gravel be for a driveway?
- A typical driveway base is 4–6 inches of compacted gravel. For heavy vehicles, use 6 inches. For pathways, 2 inches is usually sufficient.
- What's the difference between US tons and metric tonnes?
- 1 US ton = 2,000 lb. 1 metric tonne = 1,000 kg ≈ 2,204.62 lb. Most US suppliers sell by the US ton; international suppliers typically use tonnes.
- How much does a cubic yard of gravel weigh?
- Approximately 2,835 lb (1.42 US tons) for crushed stone or pea gravel. Washed gravel may be slightly lighter; crushed limestone slightly heavier.
- Why does the calculator add 10% extra?
- Gravel compacts significantly after the first rain or tamping. Ordering the exact calculated volume almost always leaves you short. The 10% allowance covers compaction, uneven subgrade, and spillage.
- Do I need a weed barrier under the gravel?
- For pathways and decorative areas, yes — a landscape fabric weed barrier prevents weeds from growing through. For driveways, a heavier geotextile separates the gravel from the subgrade and prevents rutting.