Details
Type feet and inches like 12'6" or just 12.5. Everything is saved on this device, so your list is still here in the shop.
About the mulch calculator
Mulch, topsoil, compost, gravel and sand are sold by volume: in bags of 2 or 3 cubic feet (or 40–70 litres), or loose by the cubic yard (or m³). This calculator turns the size of your beds and the depth you want into the bags to buy — and tells you when buying in bulk would be cheaper.
Add each bed as a rectangle, a circle (a tree ring) or a triangle (a corner bed). Tick Subtract for a patio or a pond inside the area. You also see the approximate weight, which matters for gravel and soil in a car or a trailer.
How to use it
- Choose Feet & inches or Metres & cm
- Enter the length and width of each bed (or the diameter of a round one)
- Pick the material and the depth you want to spread
- Choose the bag size you are buying
- Read the cubic yards (or m³), the bags and the weight — and press Copy the list
How it is worked out
Volume = area × depth. A bed 20 ft long and 4 ft wide, covered 3 inches deep, is 20 × 4 × (3 ÷ 12) = 20 cubic feet. A cubic yard is 27 cubic feet, so that is 0.74 cubic yards — or 10 bags of 2 cubic feet.
How deep to spread it
| Job | Depth |
|---|---|
| Mulch on flower beds | 2–3 in (5–8 cm) |
| Mulch to stop weeds | 3–4 in (8–10 cm) |
| Mulch around a tree (keep it off the trunk) | 2–4 in (5–10 cm) |
| Topsoil for a new lawn | 4–6 in (10–15 cm) |
| Compost dug into a bed | 2–3 in (5–8 cm) |
| Gravel path | 2–3 in (5–8 cm) |
| Gravel driveway (top layer) | 4 in (10 cm) |
| Raised bed | the full height of the bed |
Bags in a cubic yard
| Bag size | Bags for 1 cubic yard |
|---|---|
| 1.5 cu ft | 18 |
| 2 cu ft | 13.5 |
| 3 cu ft | 9 |
| 50 litres | 20 per m³ |
Mulch for common beds
3 inches deep:
| Bed | Cubic feet | Cubic yards | 2 cu ft bags | 3 cu ft bags |
|---|---|---|---|---|
| 10 × 3 ft | 7.5 | 0.28 | 4 | 3 |
| 20 × 4 ft | 20 | 0.74 | 10 | 7 |
| 10 × 10 ft | 25 | 0.93 | 13 | 9 |
| 20 × 10 ft | 50 | 1.85 | 25 | 17 |
How heavy is it?
| Material | Weight of 1 cubic yard (about) |
|---|---|
| Mulch or bark | 750 lb (0.38 tons) |
| Compost | 1,000 lb (0.5 tons) |
| Topsoil | 2,200 lb (1.1 tons) |
| Gravel or sand | 2,700 lb (1.35 tons) |
Wet material is heavier. A small pickup truck can usually carry only about half a cubic yard of gravel safely — check your vehicle's payload.
Bags or bulk?
Bags are easy for small jobs and odd corners. Above about 2 cubic yards (27 bags of 2 cu ft), buying in bulk — delivered loose by the yard — is usually much cheaper, though there is often a delivery fee.
Frequently asked questions
How much mulch do I need?
Measure the beds and choose the depth — usually 3 inches. A 10 × 10 ft bed at 3 inches needs 25 cubic feet: just under 1 cubic yard, or 13 bags of 2 cubic feet.
How many bags of mulch are in a yard?
13.5 bags of 2 cubic feet, or 9 bags of 3 cubic feet, make one cubic yard.
How much soil do I need for a raised bed?
Enter the bed's length and width, choose Topsoil (or compost) and set the depth to the height of the bed. A 4 × 8 ft bed, 12 inches deep, needs 32 cubic feet — about 1.2 cubic yards. Soil settles, so add about 10–20% extra.
How much gravel do I need for a path?
For a path 30 ft long and 3 ft wide at 3 inches deep: 22.5 cubic feet, or 0.83 cubic yards — about 1.1 tons of gravel.
How many square feet does a yard of mulch cover?
At 3 inches deep, one cubic yard covers 108 square feet; at 2 inches, 162 sq ft; at 4 inches, 81 sq ft.
Is it measured differently in metres?
Switch to Metres & cm: you get the volume in m³ and litres, bags in litres, and the weight in tonnes. One cubic metre covers 13 m² at 7.5 cm deep.
Good to know
- The weights are averages — dry mulch is much lighter than wet, and different stones differ
- Your beds and settings are saved in this browser for next time
- Nothing is sent anywhere — it works in your browser
Related tools
- Square Footage Calculator — the area of a yard or a lawn
- Concrete Calculator — for a patio or post holes
- Tile & Flooring Calculator — tiles for a patio
- Paint Calculator — paint for a fence or shed
- Wallpaper Calculator — rolls for a room
- Unit Converter — cubic yards, cubic metres and more
