Gravel Calculator

Volume = length × width × depth (or π × radius² × depth for circular areas). Convert to cubic yards by dividing by 27, then multiply by gravel density (≈1.4 tons/yd³ for standard gravel) to get tons. Add 10% for waste and compaction. For a 20 ft × 10 ft (6 m × 3 m) driveway at 4-inch (10 cm) depth: 200 sq ft × 0.333 ft = 66.7 ft³ × 1.10 = 73.3 ft³ ≈ 2.7 yd³ × 1.42 ≈ 3.9 tons. The calculator above handles all of this automatically — enter your dimensions and gravel type.

Both. Bulk gravel is usually sold by the ton (most common for driveways and large projects above ~1 yd³ / 0.76 m³). Smaller projects often use 0.5 cubic foot bags (≈14 L, ≈50 lbs / 23 kg each) from home improvement stores. The calculator above shows both yardage and bag count so you can compare bulk vs bagged pricing.

Pea gravel has rounded, smooth stones (1/8″ to 3/8″ / 3–10 mm diameter — about the size of peas). It's comfortable to walk on barefoot and good for decorative use, walkways, and playgrounds. Crushed stone has angular, sharp edges that lock together when compacted — better for driveways and structural fill where stability matters. Pea gravel rolls under foot pressure; crushed stone doesn't.

Most residential driveways need 4–6 inches (10–15 cm) of gravel total, often layered: 4 inches (10 cm) of #3 crushed stone base, then 2–3 inches (5–7.5 cm) of #57 stone, optionally finished with pea gravel for visual appeal. For heavy vehicles, poor soil, or freeze-thaw climates, go to 8–9 inches (20–23 cm) total. The calculator above defaults driveway depth to 4 inches (10 cm) — bump higher for harder service.

Most gravel weighs 1.4 to 1.5 tons per cubic yard (2,800–3,000 lbs / 1,270–1,360 kg per yd³, or roughly 1.66–1.78 tonnes per m³). Pea gravel is slightly lighter at 1.25–1.35 tons/yd³. River rock and decomposed granite are heavier at 1.5–1.6 tons/yd³. The calculator uses verified densities for each named type — see the Density Reference table below for exact values.

#57 stone is a crushed aggregate graded to roughly 3/4-inch (19 mm) pieces with some smaller fines mixed in. It's one of the most common construction aggregates because it interlocks well, drains excellently, and works for driveways, french drains, paver base, and concrete mix. The "57" comes from the ASTM D448 standard size designation — a graded sieve scheme that defines the exact particle distribution.

French drains typically need 12 inches (30 cm) of gravel — 4–6 inches (10–15 cm) below the drain pipe and 6+ inches (15+ cm) above. For a 50-foot (15 m) trench at 12 inches (30 cm) wide and 18 inches (45 cm) deep: 50 × 1 × 1.5 = 75 ft³ (2.1 m³), or roughly 3 tons of gravel. Use washed #57 stone or pea gravel — both maintain drainage. Add 10–15% extra for settling and trench irregularities.

Yes. Loose gravel compacts when laid down — typically losing 10–15% of volume. Plus there's spillage during placement and minor over-excavation. The calculator above adds 10% by default; bump to 15% for projects with heavier compaction (driveways, road bases) or irregular substrates. For tight site access where re-orders are expensive, push to 20%.

For standard gravel (105 lb/ft³ / 1,680 kg/m³): 1 ton = 2000 lbs ÷ 105 lb/ft³ = 19 ft³ ÷ 0.5 ft³/bag = 38 bags. For pea gravel (95 lb/ft³): about 42 bags per ton. Most home improvement store bags are 50 lbs (23 kg) each, so 1 ton ≈ 40 bags as a rule of thumb. Bulk delivery becomes more economical above 1–2 tons because per-bag pricing has a markup over bulk-tonnage pricing.

Yes — pick Metric in the unit selector at the top of the calculator and inputs switch to meters / centimeters, with output in cubic meters and metric tonnes (1 tonne = 1,000 kg). Custom density input switches to kg/m³. Bag count is volume-based and identical in both systems (a 0.5 ft³ bag ≈ 14 L bag). Densities are stored in lb/ft³ canonically and convert to kg/m³ at display. Your unit choice persists across pages and tabs via localStorage.