Gravel Calculator
Free gravel calculator online for driveways, pea gravel, #57 stone, French drains, and landscaping. Estimate cubic yards, tons, coverage, and cost with a compaction allowance.
Quick answer
To calculate yards of gravel: cubic yards = length × width × depth (ft) ÷ 27. A 20 × 10 driveway at 4 inches = 2.47 cubic yards (about 3.46 US tons of pea gravel at 1.4 tons/cu yd). Add 10–15% for compaction. Guides: how to calculate yards of gravel, pea gravel calculator guide, and how much gravel do I need.
Project areas
Gravel type (for weight estimate)
Density varies by stone type, moisture, and compaction. These are typical loose values — confirm with your supplier.
Results
Enter your measurements to see results.
How much gravel do I need?
To figure out how much gravel you need, calculate the volume of your project area and convert it to cubic yards or tons. Measure the length and width in feet, decide on a depth in inches, then use the formula: cubic yards = (length × width × depth in feet) ÷ 27. Add 10–15% for compaction and waste.
For example, a 20 × 10 foot driveway at 4 inches deep: 20 × 10 × 0.333 = 66.7 cubic feet ÷ 27 = 2.47 cubic yards. With 10% waste, order about 2.7 cubic yards. At a typical pea gravel density of 1.4 tons per cubic yard, that is about 3.5 US tons.
Gravel is sold by volume (cubic yards), by weight (US tons), or in bags (by cubic feet). Bulk delivery is most cost-effective for projects over about 2 cubic yards; bagged gravel suits small jobs and repairs. Full walkthrough: how much gravel do I need.
Pea gravel calculator
A pea gravel calculator uses the same yardage math with pea-gravel density (~1.4 US tons per cubic yard). Pea gravel (¼–⅜ inch rounded stone) suits paths, play areas, and decorative beds at about 2–3 inches deep. Example: 100 sq ft at 2 inches ≈ 0.62 cubic yards (~0.87 tons). Add 10% waste.
For angular driveway base stone, switch to #57 / crushed gravel density instead. Details: pea gravel calculator guide.
Gravel driveway calculator
A gravel driveway calculator should estimate base and surface layers separately. Typical residential builds use a 4–6 inch compacted crushed-stone base plus a 1–2 inch surface. Because loose gravel compacts about 20%, order 25–30% extra for the base. Cost context: gravel driveway guide.
Gravel calculator formula
Rectangular area:
Volume (cu ft) = Length (ft) × Width (ft) × (Depth (in) ÷ 12)
Cubic yards = Volume (cu ft) ÷ 27
Circular area:
Volume (cu ft) = π × Radius (ft)² × (Depth (in) ÷ 12)
Radius = Diameter ÷ 2
Weight (US tons):
Tons = Cubic yards × Density (tons per cu yd)
With waste:
Order volume = Base volume × (1 + Waste %)
Shortcut (square feet → cubic yards):
Cubic yards = Square feet × Depth (inches) ÷ 324
Worked example
Inputs: 20 ft × 10 ft driveway, 4 in depth, pea gravel (1.4 tons/cu yd)
Step 1 — volume: 20 × 10 × (4 ÷ 12) = 66.67 cu ft = 2.47 cu yd
Step 2 — with 10% waste: 2.47 × 1.10 = 2.72 cu yd to order
Step 3 — weight: 2.47 × 1.4 = 3.46 US tons (or 3.81 tons with waste)
Cost at $50/ton: 3.81 × $50 ≈ $190 (material only, before delivery)
Gravel calculator in yards
Cubic yards are the standard unit for bulk gravel orders. To calculate yards of gravel, multiply your project area (length × width in feet) by the depth in feet, then divide by 27. The shortcut formula — cubic yards = square feet × depth (inches) ÷ 324 — combines the inch-to-feet and cubic-feet-to-yards conversions into one step.
For example, 200 square feet at 4 inches: 200 × 4 ÷ 324 = 2.47 cubic yards. Most suppliers have a minimum delivery of 1–3 cubic yards, and bulk loads are typically delivered in 10–25 cubic yard dump trucks.
Gravel calculator in tons
Many suppliers sell gravel by the US ton (2,000 lb). To convert cubic yards to tons, multiply by the material's density. Gravel density varies by stone type, gradation, moisture, and compaction — there is no single universal value. The table below shows typical loose, dry densities; always confirm the exact value with your supplier.
Example: 5 cubic yards of pea gravel at 1.4 tons/cu yd = 7.0 US tons. The same 5 cubic yards of river rock at 1.25 tons/cu yd = only 6.25 tons — a 10% difference that matters when budgeting.
| Material | lb / cu yd | US tons / cu yd | Common uses |
|---|---|---|---|
| Pea gravel | 2,800 | 1.40 | Paths, play areas, drainage |
| Crushed stone (¼–1 in) | 2,700 | 1.35 | Driveway base, paver base |
| Crushed stone (1–2 in) | 2,500 | 1.25 | Drainage, French drains |
| #57 washed gravel | 2,700 | 1.35 | Driveways, concrete aggregate |
| River rock | 2,500 | 1.25 | Landscaping, dry creek beds |
| Bank run gravel | 3,000 | 1.50 | Base fill, roadways |
| Decomposed granite | 2,600 | 1.30 | Paths, patios, xeriscaping |
| Limestone (crushed) | 2,600 | 1.30 | Driveways, base material |
Densities are typical loose, uncompacted values for dry material. Wet gravel weighs more; compacted gravel is denser. These are estimates for planning — not material specifications. Confirm actual density with your supplier before purchasing.
Gravel coverage calculator
Coverage tells you how much surface area a given quantity of gravel will cover at a specific depth. One cubic yard covers 81 square feet at 4 inches deep; one US ton (at 1.4 tons/cu yd) covers about 58 square feet at the same depth. Coverage drops quickly as depth increases — doubling depth halves the area.
To find coverage for your order: divide the cubic yards (or tons × 0.71) by 27, then divide by the depth in feet. Or use the table below for common depths.
| Depth | Sq ft per cubic yard | Sq ft per US ton* |
|---|---|---|
| 1 inch | 324 | 231 |
| 2 inches | 162 | 116 |
| 3 inches | 108 | 77 |
| 4 inches | 81 | 58 |
| 6 inches | 54 | 39 |
*Per-ton coverage assumes 1.4 tons/cu yd (typical pea gravel). Actual coverage varies with density.
Gravel cost calculator
To estimate gravel cost, multiply the quantity by the unit price. Bulk gravel in the US typically costs $15–$75 per ton or $20–$50 per cubic yard, depending on the stone type and your location. Delivery is usually an additional flat fee of $30–$100 depending on distance. Bagged gravel runs $4–$8 per 0.5 cu ft bag — equivalent to $200–$400+ per cubic yard, so bags only make sense for small jobs.
Example: A driveway needing 3.81 tons of pea gravel at $50/ton = $190.50 for material, plus a $60 delivery fee = $250.50 total. The same project in bagged gravel (about 206 bags at $5 each) would cost over $1,000.
Prices vary significantly by region and stone availability. Get quotes from 2–3 local suppliers, and ask whether the price is per ton or per cubic yard — the difference matters when comparing.
Gravel driveway calculator
A residential gravel driveway is built in layers: a 4–6 inch compacted base of crushed stone, topped with a 1–2 inch surface layer of smaller gravel. Calculate each layer separately — the base is thicker and uses denser stone, while the surface is shallower and uses a finer, more decorative material.
Because loose gravel compacts about 20%, order 25–30% more than the compacted target volume for the base layer. A 20 × 10 driveway base at 6 inches compacted = 3.7 cubic yards compacted, so order about 4.6–4.8 cubic yards loose. The surface layer at 2 inches adds about 1.2 cubic yards.
For a standard 2-car driveway (roughly 20 × 40 feet, or 800 sq ft), expect to order 11–16 cubic yards of base material and 3–5 cubic yards of surface gravel, depending on depth and compaction.
Recommended gravel depth by project
Depth is the single biggest factor in how much gravel you need. Use these typical ranges as a starting point, then adjust for your soil type, drainage, and traffic.
| Project | Typical depth | Notes |
|---|---|---|
| Driveway base | 4–6 in | Compacted; order 25–30% extra loose |
| Driveway surface | 1–2 in | Top layer over a compacted base |
| Garden path | 2–3 in | Over landscape fabric |
| Patio paver base | 4–6 in | Compacted, plus 1 in sand |
| French drain | 8–12 in | Washed #57 stone preferred |
| Landscaping bed | 2–3 in | Over weed barrier fabric |
| Drainage trench | 6–12 in | Depends on water volume |
| Shed base | 4–6 in | Compacted, leveled |
Gravel for common projects
Driveways
A residential gravel driveway needs a 4–6 inch compacted base plus a 1–2 inch surface layer. Calculate each layer separately. For a 20 × 10 driveway, the base at 6 inches is about 3.7 cu yd; the surface at 2 inches adds about 1.2 cu yd.
Garden paths
Path gravel is typically 2–3 inches deep over landscape fabric. A 10 × 4 foot path at 3 inches needs about 0.37 cu yd. Use pea gravel or decomposed granite for comfortable walking.
Paver bases
Patio and walkway pavers need a 4–6 inch compacted gravel base (often #57 crushed stone) plus a 1-inch sand setting bed. Calculate the gravel volume separately from the sand.
French drains
French drains use washed #57 gravel (no fines) to allow water flow. Trench volume = width × depth × length ÷ 27, minus the volume of the perforated pipe. Account for the pipe diameter.
Landscaping beds
Decorative gravel in beds is 2–3 inches deep over weed barrier. Calculate the bed area × depth, then choose river rock, pea gravel, or decomposed granite based on the look you want.
Shed bases
A gravel pad for a shed is typically 4–6 inches of compacted crushed stone, slightly larger than the shed footprint. This provides drainage and a level base for the floor joists.
Calculating gravel for circular areas
For round fire pits, circular patios, and round garden beds, use the cylinder formula: cubic yards = (π × radius² × depth in feet) ÷ 27. Measure the radius as half the diameter (the full width across the circle).
Example
A 10-foot-diameter fire pit (5 ft radius) at 4 inches deep: π × 5² × 0.333 = 26.18 cubic feet ÷ 27 = 0.97 cubic yards. At 1.4 tons/cu yd, that is about 1.36 tons.
Bagged gravel calculator
For small projects, bagged gravel from a home center is convenient but more expensive per cubic yard. Bags are sold by cubic feet, so divide your total cubic feet by the bag size. One cubic yard (27 cubic feet) equals 54 half-cubic-foot bags.
| Bag size | Cubic feet per bag | Bags per cubic yard |
|---|---|---|
| 0.5 cu ft | 0.50 | 54 |
| 0.75 cu ft | 0.75 | 36 |
| 1.0 cu ft | 1.00 | 27 |
| 1.5 cu ft | 1.50 | 18 |
A 2.47 cubic yard driveway order equals about 133 half-cubic-foot bags — bulk delivery is almost always cheaper at that scale.
Accounting for compaction
Loose gravel delivered by truck takes up more volume than the same gravel after it is placed and compacted. A typical compaction factor is 20–25% — meaning 5 cubic yards of loose gravel becomes about 4 cubic yards after compaction.
If your project specifies a compacted depth (for example, a 4-inch compacted driveway base), order 25% more loose material to end up with the target compacted volume. The waste percentage in the calculator can represent this compaction allowance, or you can calculate it separately.
Pea gravel calculator
Pea gravel is small, rounded stone (¼–⅜ inch) used for garden paths, play areas, dog runs, and decorative beds. It’s smooth to walk on but shifts underfoot, so it’s not ideal for driveways without edging. Pea gravel density is about 1.4 US tons per cubic yard.
To calculate pea gravel, use the standard formula: area × depth ÷ 27 for cubic yards. A 100 sq ft path at 2 inches: 100 × 0.167 = 16.7 cubic feet ÷ 27 = 0.62 cubic yards (about 0.87 tons). For a 200 sq ft patio at 3 inches, order about 2.3 cubic yards (3.2 tons). Add 10% for waste.
#57 gravel calculator
#57 washed gravel is crushed stone (¾–1 inch) with angular edges that locks together when compacted. It’s the standard choice for driveway bases, concrete aggregate, French drains, and paver bases. #57 gravel density is about 1.35 US tons per cubic yard.
For a 200 sq ft driveway base at 4 inches of #57: 200 × 0.333 = 66.7 cubic feet ÷ 27 = 2.47 cubic yards (about 3.3 tons). Add 10–15% for compaction. #57 is sold by the ton at most quarries and landscape yards.
French drain gravel calculator
A French drain uses washed #57 gravel (no fines) to allow water flow. Calculate the trench volume minus the pipe volume:
Gravel = (trench length × width × depth) − (pipe volume) ÷ 27
For a 50-foot trench that is 12 inches wide and 18 inches deep with a 4-inch pipe: trench = 50 × 1 × 1.5 = 75 cubic feet; pipe = 50 × 0.333 × 0.333 = 5.5 cubic feet; gravel = 75 − 5.5 = 69.5 cubic feet ÷ 27 = 2.57 cubic yards. Use washed #57 stone — crushed stone with fines will clog the drain.
How much gravel under a concrete slab?
A gravel base under a concrete slab is typically 4–6 inches of crushed stone (#57 or similar). It provides drainage, prevents settling, and distributes the slab’s load. For a 10 × 10 slab at 4 inches of gravel: 10 × 10 × 0.333 = 33.3 cubic feet ÷ 27 = 1.23 cubic yards. Add 10% for compaction, so order about 1.4 cubic yards.
For a 24 × 24 garage slab at 6 inches of gravel: 24 × 24 × 0.5 = 288 cubic feet ÷ 27 = 10.67 cubic yards. Order about 12 cubic yards with compaction. Compact the gravel in 2-inch layers before pouring concrete.
Gravel for pavers and retaining walls
Paver base: A paver base needs 4–6 inches of compacted gravel (typically #57 crushed stone) plus 1 inch of sand. For a 12 × 12 patio at 6 inches of gravel: 12 × 12 × 0.5 = 72 cubic feet ÷ 27 = 2.67 cubic yards. Add 25% for compaction, so order about 3.3 cubic yards of gravel plus 0.44 cubic yards of sand.
Retaining wall: A gravel retaining wall needs a base trench (6 inches deep × 2× the wall width) and drainage gravel behind the wall (1 foot wide × wall height). For a 20-foot wall with 6-inch base: 20 × 1 × 0.5 = 10 cubic feet ÷ 27 = 0.37 cubic yards for the base, plus drainage gravel behind the wall. Use #57 crushed stone.
Gravel calculator from square feet
To calculate gravel from square feet, multiply the area by the depth in feet, then divide by 27 for cubic yards. The shortcut formula: cubic yards = square feet × depth (inches) ÷ 324. For 200 sq ft at 4 inches: 200 × 4 ÷ 324 = 2.47 cubic yards.
Multiply cubic yards by the gravel density (1.25–1.5 tons per cubic yard) for weight. At 1.4 tons/cu yd, 2.47 cubic yards = 3.46 US tons. Add 10–15% for compaction and waste.
Related volume calculators & guides
Volume math: cubic yard calculator. Paving: asphalt calculator. Fill/topsoil: dirt calculator. Convert square feet to cubic yards or cubic yards to tons. Guides: how to calculate yards of gravel, pea gravel calculator guide, how much gravel do I need, and gravel driveway guide.
Frequently asked questions
Related guides
Learn the math behind this calculator with our step-by-step guides.