This gravel calculator tells you exactly how much gravel you need for a driveway, patio base, walkway, or French drain. Enter the length and width of the area in feet and the depth in inches, pick your material, and it returns the volume in cubic yards and cubic feet plus the weight in tons — the two units suppliers actually quote.
It also works as a stone calculator for crushed stone, pea gravel, river rock, sand, and fill dirt, each with its own typical density. The depth chart shows how the order size changes at 2, 3, and 4 inches so you can balance coverage against cost before you call the quarry.
How to Figure Out How Much Gravel You Need
Gravel is sold by volume (cubic yards) or by weight (tons), so the math has two steps.
- Volume: cubic yards = length (ft) × width (ft) × depth (ft) ÷ 27. Convert the depth from inches to feet first by dividing by 12.
- Weight: tons = cubic yards × material density. Crushed stone and pea gravel run about 1.4 tons per cubic yard; river rock and sand about 1.35; loose fill dirt about 1.1.
For example, a 20 × 10 ft area at 3 inches deep is 20 × 10 × 0.25 = 50 cubic feet, or 1.85 cubic yards, which weighs roughly 2.6 tons in crushed stone. If your area is irregular, split it into rectangles, calculate each, and add the results together.
Gravel Depth Guide by Project
Depth is the number most people get wrong, and it drives both cost and performance. Common recommendations:
- Walkways and paths: 2–3 inches of pea gravel or crushed stone.
- Patio and paver base: 4 inches of compacted crushed stone.
- Residential driveways: 4–6 inches total, ideally in two or three compacted layers (larger #3 stone below, 3/4-inch crushed stone on top).
- French drains: 3–4 inches of washed gravel under and around the pipe.
- Landscape cover over fabric: 2 inches of river rock or pea gravel.
Going from 2 to 4 inches doubles the tonnage, so measure the area carefully and use the depth chart above to compare order sizes before committing.
Worked Example: Gravel for a 20 × 10 ft Parking Pad
Say you are building a 20 ft long, 10 ft wide parking pad with 4 inches of crushed stone.
Step 1 — volume in cubic feet: 20 × 10 × (4 ÷ 12) = 66.7 cu ft. Step 2 — convert to cubic yards: 66.7 ÷ 27 = 2.47 yd³. Step 3 — convert to tons: 2.47 × 1.4 = 3.46 tons. Step 4 — add 5% for compaction and spillage: about 2.6 yd³ or 3.6 tons.
At a typical price of $40–$60 per ton delivered, this pad would cost roughly $145–$220 in material. A full-size pickup truck carries about half a ton to one ton of gravel, so an order this size is usually cheaper to have delivered.
Frequently Asked Questions
How much gravel do I need for a 10x20 area?
A 10 × 20 ft area needs about 1.85 cubic yards (2.6 tons) of gravel at 3 inches deep, or 2.47 cubic yards (3.5 tons) at 4 inches deep. Multiply length × width × depth in feet, divide by 27 for cubic yards, then multiply by 1.4 to estimate tons of crushed stone.
How many tons of gravel are in a cubic yard?
One cubic yard of gravel weighs about 1.4 tons (2,800 lb) for crushed stone or pea gravel, 1.35 tons for river rock or sand, and roughly 1.1 tons for loose fill dirt. Wet material weighs more, so allow extra if the gravel has been rained on.
How many cubic yards are in a ton of gravel?
A ton of gravel is about 0.71 cubic yards of crushed stone or pea gravel (1 ÷ 1.4). At 3 inches deep, one ton covers roughly 77 square feet; at 2 inches deep it covers about 115 square feet.
How deep should gravel be for a driveway?
A gravel driveway should be 4–6 inches deep in total, built as two or three compacted layers: a base of larger #3 stone, an optional middle layer of #57 stone, and a top layer of 3/4-inch crushed stone with fines that locks together under traffic.
How much does a cubic yard of gravel cover?
One cubic yard of gravel covers about 162 square feet at 2 inches deep, 108 square feet at 3 inches, and 81 square feet at 4 inches. Divide 324 by the depth in inches to get the coverage in square feet per cubic yard.