How to use this calculator
Choose the material, enter the area (length × width or square feet) and the depth you want, and the calculator returns cubic yards, cubic feet, the number of bags for the bag size you select, and the approximate weight. Enter a bulk price per yard or a price per bag to compare — bulk delivery usually wins above about two yards.
The maths
cubic feet = area (sq ft) × depth (in) ÷ 12
cubic yards = cubic feet ÷ 27
bags = cubic feet ÷ bag size (cu ft)
weight = cubic feet × density (lb/cu ft)A common mistake is forgetting to convert depth from inches to feet — 3 inches is 0.25 ft, not 3.
Recommended depths
| Use | Depth |
|---|---|
| Mulch around plants and beds | 2–3 in (3 in for weed suppression) |
| Mulch under trees | 3–4 in, kept away from the trunk |
| Playground wood chips | 9–12 in for fall protection |
| Gravel path | 2–3 in over landscape fabric |
| Gravel driveway | 4 in over 4 in of compacted base |
| Topsoil for new lawn | 4–6 in |
| Topsoil to level a lawn | 1/2–1 in per application |
| Paver base (crushed stone) + sand | 4–6 in base + 1 in sand |
| Decorative river rock | 2–3 in |
Typical weights per cubic yard
| Material | Weight |
|---|---|
| Bark / wood mulch | 500–800 lb |
| Compost | 1,000–1,400 lb |
| Topsoil (dry) | 2,000 lb |
| Sand | 2,600–2,800 lb |
| Pea gravel / river rock | 2,600–2,800 lb |
| Crushed stone / road base | 2,700–3,000 lb |
The calculator uses mid-range densities. Wet material is noticeably heavier. A half-ton pickup carries about half a cubic yard of gravel safely but a full yard or more of mulch.
Bulk or bags?
- Bags are convenient for small beds and easy to store; expect to pay 2–3× the bulk price per cubic yard.
- Bulk (delivered by the yard or ton) is cheaper for anything over 1.5–2 yards, but you need a place to dump it and a wheelbarrow afternoon to move it.
- Many suppliers sell stone by the ton; the weight figure here converts for you.
Measure irregular beds with the square footage calculator first. Pouring a slab instead? Use the concrete calculator.
Frequently asked questions
How much mulch do I need for 200 square feet?
At the recommended 3-inch depth, 200 sq ft needs 50 cubic feet — 1.85 cubic yards, or 25 bags of 2 cu ft. Two cubic yards delivered in bulk is usually cheaper than 25 bags.
How many bags of mulch are in a cubic yard?
13.5 bags of 2 cu ft, or 27 bags of 1 cu ft. A cubic yard is 27 cubic feet.
How deep should mulch or gravel be?
Mulch 2–4 inches (3 is typical; deeper suffocates roots). Gravel paths and drives 3–4 inches over a compacted base. Topsoil 4–6 inches for new lawns and beds. Sand under pavers 1 inch.
How much does a cubic yard weigh?
Mulch about 500–800 lb; topsoil roughly 2,000 lb; gravel and crushed stone 2,700–3,000 lb; sand about 2,700 lb. Weight matters for delivery pricing (stone is often sold by the ton) and for what your vehicle can carry.
Last updated August 27, 2026.