How to calculate how much gravel you need
The math is simple: volume = area × depth. Measure the length and width of your area, pick a depth, and multiply. This calculator does it for you and converts the result into the units suppliers actually use — cubic yards, tons, and 0.5 cubic foot bags — plus an estimated cost so you don't overspend at the yard.
The formula, step by step
1. Area = length × width (in feet) for a rectangle, or π × radius² for a circle.
2. Volume in cubic feet = area × (depth in inches ÷ 12).
3. Cubic yards = cubic feet ÷ 27 (suppliers sell bulk gravel by the yard).
4. Tons = cubic yards × material density (gravel is roughly 1.4 tons per yard).
How deep should gravel be?
For a walkable path, 2 inches is usually enough. For a driveway, aim for 4 inches over a compacted base — more if heavy vehicles use it. Decorative ground cover and drainage beds typically use 2–3 inches. Going deeper than you need is the most common way people waste money on gravel.
Material density reference
| Material | Approx. weight | Common use |
|---|---|---|
| 🪨 Pea Gravel | ~1.3 tons/yd³ | Paths, patios |
| 🧱 Crushed Stone | ~1.4 tons/yd³ | Driveways, base |
| ⚪ River Rock | ~1.4 tons/yd³ | Drainage, decor |
| 🏖️ Sand | ~1.35 tons/yd³ | Paver base, fill |
| 🟤 Topsoil | ~1.1 tons/yd³ | Gardens, lawns |
| 🍂 Mulch | ~0.5 tons/yd³ | Garden beds |
Bagged vs. bulk gravel
Bagged gravel (sold in 0.5 cubic foot bags) is convenient for small jobs but costs much more per cubic yard. As a rough rule, once you need more than about 10–15 bags, ordering bulk delivery by the cubic yard or ton is cheaper. Always add about 5–10% extra to cover compaction and uneven ground.
Gravel coverage: how much area one yard covers
Coverage depends entirely on depth — a single cubic yard of gravel spreads much further at 2 inches than at 4. Use this gravel coverage chart to sanity-check the calculator's yardage before you order.
| Depth | 1 yd³ covers | 1 ton covers |
|---|---|---|
| 1 inch | ~324 sq ft | ~240 sq ft |
| 2 inches | ~162 sq ft | ~120 sq ft |
| 3 inches | ~108 sq ft | ~80 sq ft |
| 4 inches | ~81 sq ft | ~60 sq ft |
| 6 inches | ~54 sq ft | ~40 sq ft |
Ton figures assume typical gravel at about 1.4 tons per cubic yard; lighter or heavier materials shift coverage a little.
Gravel calculator for any project — driveways, pathways, and landscaping
Gravel calculator for driveways
A standard driveway (10 ft × 20 ft) requires about 6–8 cubic yards of gravel for a 4-inch base layer. Use this calculator to enter your driveway dimensions and desired depth; it returns the cubic yards and tons needed. For a 2-inch layer (common for top-up), use roughly half the amount.
Gravel calculator for landscaping and garden beds
Garden beds and decorative areas typically need 2–3 inches of gravel. A 10 ft × 10 ft bed at 2.5 inches depth requires about 0.62 cubic yards. The calculator helps you avoid over-buying or under-buying decorative gravel, river rock, or pea gravel for flower beds.
Gravel calculator for pathways and walkways
Garden pathways usually need 2–4 inches of gravel, depending on traffic. A 3-foot-wide path that's 50 feet long at 3 inches deep requires about 1.85 cubic yards. Thicker pathways (4 inches) are more durable under heavy foot traffic.
How much gravel do I need for a 4-car driveway?
A 4-car driveway is roughly 20 ft × 40 ft. For a 4-inch gravel base, you'll need about 24–30 cubic yards (or 36–45 tons, depending on gravel type). Many contractors recommend a 2-inch layer as a yearly top-up maintenance; factor that into your budget.
Gravel calculator — cubic yards vs. tons
Cubic yards measure volume; tons measure weight. One cubic yard of gravel typically weighs 1.3–1.5 tons, depending on the type (crushed stone is heavier than pea gravel). This calculator converts between the two, so you know exactly how much to order from your supplier.
Pea gravel vs. crushed stone vs. river rock
Pea gravel is smooth and comfortable to walk on but shifts easily; crushed stone locks in place and is better for driveways; river rock is decorative and expensive. All three occupy the same volume, so cubic yard calculations are identical — weight varies slightly. Choose based on your project (driveway, walkway, or decoration) and budget.
Gravel cost calculator
Gravel costs $20–$50 per ton delivered, depending on type and location. For a 30-ton driveway base, expect $600–$1,500 in material costs, plus $100–$200 for delivery. Use cubic yardage to get a quick cost estimate from local suppliers.
Limestone vs. marble chips vs. decomposed granite
Limestone is affordable and good for driveways ($15–$25/ton). Marble chips are decorative but pricey ($50–$100+/ton). Decomposed granite is excellent for pathways and compacts well ($20–$40/ton). All calculate the same way by volume; choose based on appearance and budget.
French drain gravel and base layers
French drains and landscape base layers require 1–2 sizes of gravel: coarse (at the bottom for drainage) and finer (on top). Many projects use 3–4 inches of coarse gravel plus 2–3 inches of finer material. This calculator handles the math for the total volume needed.
Methodology & sources
How this calculator works: area from your shape (rectangle L×W, circle πr², triangle ½×base×height, or direct area) × depth = in-place volume; order volume = in-place volume × (1 + compaction%) × (1 + waste%); weight = cubic yards × material density (tons/yd³). Default densities: pea gravel 1.3, crushed stone 1.4, river rock 1.4, sand 1.35, topsoil 1.1, mulch 0.5 — or enter your supplier's exact figure with the Custom material. Compaction guidance follows common aggregate-industry practice (crushed stone compacts roughly 10–15%). Cost estimates are price × weight, not quotes. Last reviewed: by the Toolchive Team.
Frequently asked questions
How much gravel do I need?
Multiply area by depth. Volume in cubic feet = length × width × (depth in inches ÷ 12); divide by 27 to get cubic yards. The calculator also converts this into tons and bags.
How much area does a yard of gravel cover?
One cubic yard covers about 162 sq ft at 2 inches deep, 108 sq ft at 3 inches, or 81 sq ft at 4 inches. Coverage drops as depth increases.
How do I calculate gravel yardage?
Gravel yardage is your volume in cubic yards: length × width × depth (in feet) ÷ 27. For a 20 × 10 ft area at 3 inches deep, that's about 1.85 cubic yards.
How deep should gravel be?
About 2 inches for a walkable path, and 4 inches for a driveway over a compacted base — more if heavy vehicles use it.
How much does a cubic yard of gravel weigh?
Roughly 1.4 tons for typical gravel and crushed stone. Pea gravel is about 1.3 tons, topsoil about 1.1 tons, and mulch about 0.5 tons per cubic yard.