Mulch Calculator
Enter the size of your bed and how deep you want the mulch to get the cubic yards, cubic feet and number of bags you need.
Buying mulch by volume is much cheaper than by the bag for larger beds, but bags are handy for small jobs. This calculator gives you both so you can compare.
How to calculate how much mulch you need
Mulch is sold by volume, so you multiply the area of your bed by the depth you want, then convert to cubic yards (how bulk mulch is sold) or bags.
Cubic feet = Area (sq ft) × Depth (inches) ÷ 12
Cubic yards = Cubic feet ÷ 27
Bags = Cubic feet ÷ bag size (2 cu ft is standard)
Cubic yards = Cubic feet ÷ 27
Bags = Cubic feet ÷ bag size (2 cu ft is standard)
| Depth | Best for |
|---|---|
| 1–2 inches | Refreshing existing mulch |
| 2–3 inches | General beds and around plants |
| 3–4 inches | Weed suppression and bare beds |
Worked example
A 20 ft × 10 ft bed at 3 inches deep:
| Area = 20 × 10 | 200 sq ft |
| Cubic feet = 200 × 3 ÷ 12 | 50 cu ft |
| Cubic yards = 50 ÷ 27 | ≈ 1.9 yd³ |
| Bags (2 cu ft) | 25 bags |
Feet or metres?
Use the Feet / Metres toggle. In metric, enter the bed in metres and depth in centimetres; results are shown in cubic metres and litres.
Frequently asked questions
How many bags of mulch are in a cubic yard?
A cubic yard is 27 cubic feet, so it equals about 13–14 bags of the standard 2-cubic-foot size, or about 9 of the 3-cubic-foot bags.
How deep should mulch be?
2–3 inches is ideal for most beds. Go up to 3–4 inches for weed control, but keep mulch a couple of inches away from plant stems and tree trunks.
How much does a cubic yard of mulch cover?
One cubic yard covers about 100 sq ft at 3 inches deep, 160 sq ft at 2 inches, or 320 sq ft at 1 inch.
Related calculators
Results are estimates. Order about 10% extra to allow for settling and uneven ground.