How to use the gravel calculator
- Pick your gravel type — crushed stone, pea gravel, river rock or decomposed granite each have a different weight.
- Choose a shape (rectangle, circle, triangle or a ring for a border) and enter the dimensions in feet, inches, yards, metres or centimetres.
- Enter the depth you plan to lay.
- Got more than one area, like a driveway and a path? Press Add another area — they're added together.
- Read the result in cubic yards, cubic feet, tons and bags, tick a waste allowance if you like, and enter a price to see the estimated cost.
Only need the square footage first? Use the square footage calculator, then come back and enter the depth here.
How much gravel do I need? The formula
Cubic yards = length (ft) × width (ft) × depth (ft) ÷ 27. Tons = cubic yards × the gravel's density.
- Measure length and width in feet, and depth in inches (divide by 12 to get feet).
- Multiply length × width × depth to get cubic feet, then divide by 27 for cubic yards.
- Multiply cubic yards by the density (tons per cubic yard) for the weight.
Worked example: a 20 × 10 ft driveway apron at 4 in deep, using crushed stone (#57) at 1.4 tons per cubic yard: 20 × 10 × (4 ÷ 12) = 66.67 cu ft, ÷ 27 = 2.47 cubic yards, × 1.4 = 3.46 tons. Add a 10% compaction allowance and that becomes 2.72 cubic yards.
Gravel types and recommended depths
| Gravel type | Typical density | Recommended depth | Best for |
|---|---|---|---|
| Crushed stone (#57) | 1.4 tons/yd³ | 4–6 in | Driveways, drainage and paths: 4–6 in per compacted layer, 8–12 in total for a new driveway base. |
| Pea gravel | 1.3 tons/yd³ | 2–3 in | Paths, patios and play areas: 2–3 in deep. |
| River rock | 1.33 tons/yd³ | 2–4 in | Decorative beds, dry creek beds and drainage: 2–4 in deep. |
| Decomposed granite | 1.6 tons/yd³ | 2–4 in | Paths and patios, usually compacted in layers: 2–4 in deep, plus extra for compaction. |
Typical, widely published values — actual density depends on moisture and how the gravel is compacted. Ask your supplier for their exact figure, especially for a paid order.
Gravel calculator tons vs. cubic yards
Suppliers price gravel either by the ton or by the cubic yard, and the two describe the same pile of material once you know the density. Denser gravel weighs more for the same volume: crushed stone at 1.4 tons per cubic yard weighs more than pea gravel at 1.3 tons per cubic yard for the same size hole. If a supplier only quotes by the ton, use the calculator's tons figure directly; if they quote by the yard, use the cubic yards figure.
Driveways, paths and patios: how deep should gravel be?
- Paths and walkways: 2–3 in of pea gravel or crushed stone over landscape fabric.
- Standard driveways: 4–6 in of crushed stone, compacted in layers rather than dumped all at once.
- New driveways: 8–12 in total — a coarser base layer (often #3 or #4 stone) topped with 2–4 in of a finer finish stone like #57.
- Patios and fire pits: 2–3 in of pea gravel or decomposed granite, often edged to stop it spreading. A 12 ft circular patio at 3 in deep needs about 1.05 cubic yards of pea gravel.
Small path example: a 3 × 25 ft path at 2 in deep with pea gravel needs about 0.46 cubic yards (12.5 cu ft) — small enough that bagged gravel (about 25 bags at 0.5 cu ft, or 25 bags at 50 lb) can be cheaper than a bulk delivery minimum.
Other landscaping calculators
- Laying mulch around the same beds? Try the mulch calculator.
- Need topsoil for a lawn or raised bed first? Try the topsoil calculator.
- Bedding sand under pavers? Try the sand calculator.
- Pouring a slab instead? Try the concrete calculator.
- Just need the area, not the material? Try the square footage calculator.
Frequently asked questions
How much gravel do I need?
Multiply the area in square feet by the depth in feet, then divide by 27 to get cubic yards, and multiply by the material's density to get tons. For a 20 × 10 ft driveway apron at 4 in deep with crushed stone (#57, 1.4 tons per cubic yard), that's 2.47 cubic yards, or about 3.46 tons. The gravel calculator above does this for any shape and depth.
How many tons of gravel do I need for my driveway?
Tons = cubic yards × the density of the gravel you're using. Crushed stone (#57) is about 1.4 tons per cubic yard, so a 20 × 10 ft driveway apron at 4 in deep needs roughly 3.46 tons (2.47 cu yd). Densities vary by supplier and by how wet the gravel is, so always confirm the exact figure before you order a paid delivery.
How deep should a gravel driveway be?
Most gravel driveways use 4 to 6 inches of crushed stone laid on top of a compacted base, and a new driveway built from scratch often needs 8 to 12 inches total across a base layer and a topping layer. Walkways and paths typically need only 2 to 3 inches, since they carry foot traffic rather than vehicles.
Should I order gravel by the ton or by the cubic yard?
Most bulk suppliers sell gravel by the ton, while some landscaping yards quote by the cubic yard. They describe the same pile of gravel: multiply cubic yards by the density (tons per cubic yard) to convert. For the driveway example above, 2.47 cu yd of crushed stone is about 3.46 tons; a lighter material like pea gravel (1.3 tons per cubic yard) weighs less for the same volume.
How many bags of gravel do I need?
For small jobs, bagged gravel is easier than a bulk delivery. A garden path 3 × 25 ft at 2 in deep with pea gravel needs about 0.46 cubic yards (12.5 cu ft), which is around 25 bags at 0.5 cu ft each, or 25 bags of 50 lb gravel. The calculator lists bag counts for 0.5, 0.75, 1, 1.5 and 2 cu ft bags plus 50 lb bags, always rounded up so you don't come up short.
What's the difference between pea gravel, crushed stone and river rock?
Pea gravel is small, rounded and comfortable to walk on, so it suits paths, patios and play areas. Crushed stone (like #57) has angular edges that lock together under compaction, which is why it is used for driveways and drainage. River rock is larger and rounded, mostly decorative — dry creek beds, edging and borders. Each has a different density, so switch the gravel type in the calculator above to get the right weight.
How much gravel covers a circular patio or fire pit?
Area = π × (diameter ÷ 2)². A 12 ft diameter circle at 3 in deep with pea gravel covers about 113 sq ft and needs roughly 1.05 cubic yards (1.36 tons). Choose "Circle" as the shape in the calculator and enter the diameter, not the radius.
Should I add extra gravel for compaction or waste?
Yes — most suppliers recommend an extra 5 to 10% to allow for compaction, uneven ground and spillage. Tick "Add a waste / compaction allowance" in the calculator. With a 10% allowance, the driveway example above goes from 2.47 to 2.72 cubic yards.
How do I measure an irregular area for gravel?
Split it into simple shapes — rectangles, circles, triangles or a ring for a border around a bed or tree — and use "Add another area" in the calculator to add them together. If you only need the square footage rather than a material estimate, the square footage calculator is a quicker way to measure first.
Is my data saved or sent anywhere?
Your measurements are saved only in your own browser, so they are there next time you open this page on the same device. Nothing is sent to our servers.