Gravel depth by project type
Depth drives volume more than any other variable. A decorative path might need 2–3 inches of pea gravel over landscape fabric. A driveway for passenger vehicles often needs 4–6 inches of crushed stone after compaction, sometimes over a separate base layer.
Always measure depth after compaction expectations — loose stone settles 10–20% when driven on. Many pros order extra for regrading after the first month.
- Walking paths: 2–3 inches surface gravel
- Patios (gravel): 3–4 inches over compacted base
- Light-duty driveway: 4–6 inches crushed stone
- Heavy use / soft soil: 6–8 inches + geotextile
Driveway area calculation
Measure length × width of the tire track area or full pad. A 12 ft × 40 ft single-lane strip = 480 sq ft. At 5 inches (0.417 ft) depth: 480 × 0.417 = 200 cu ft ≈ 7.4 cubic yards. Add 10% → about 8.2 yards.
Curved drives can be approximated as rectangles or split into sections. Use our gravel calculator for multiple areas.
Base layer vs surface stone
Full driveway builds may use 4 inches of large crushed base (#2 or #3 stone) plus 2 inches of finer topping (#57 or pea gravel). Calculate each layer separately — they are often different products and prices.
For mulch-site math, the same L×W×depth÷27 formula applies; only depth targets and compaction allowance change.