Mulch calculator
This mulch calculator turns the size of your garden beds and the depth you want into cubic yards of bulk mulch, or the number of 2 and 3 cubic foot bags to buy.
- Rectangular or round beds, or total square feet
- Cubic yards for bulk delivery
- Bag counts for 2 and 3 cubic foot bags
Last updated
How to use the mulch calculator
- Choose the bed shape. For several beds, add up their square feet and use the “Square feet” option.
- Enter the length and width (or diameter) in feet.
- Enter the depth in inches. 2 to 3 inches suits most planting beds.
- Add a few percent extra if the mulch is fluffy and will settle, then read the cubic yards for bulk delivery or the bag count for 2 or 3 cubic foot bags.
How to calculate mulch
Multiply the bed’s area by the depth in feet to get cubic feet, then divide by 27 for cubic yards, the unit bulk mulch is sold in.
cubic yards = length (ft) × width (ft) × depth (in ÷ 12) ÷ 27
For bags, divide the cubic feet by the bag size and round up. A cubic yard holds 13.5 bags of 2 cubic feet, or 9 bags of 3 cubic feet. For a round bed, the area is 3.1416 × (diameter ÷ 2)².
Worked example
A 20 × 10 ft bed covered 3 inches deep.
- Area: 20 × 10 = 200 sq ft.
- Volume: 200 × (3 ÷ 12) = 50 cubic feet.
- Cubic yards: 50 ÷ 27 = 1.85 cubic yards.
- Bags: 50 ÷ 2 = 25 bags of 2 cu ft, or 50 ÷ 3 = 16.7, so 17 bags of 3 cu ft.
For bulk, round up to 2 cubic yards.
How far a cubic yard of mulch goes
| Depth | Sq ft per cubic yard | Sq ft per 2 cu ft bag | Sq ft per 3 cu ft bag |
|---|---|---|---|
| 1 in | 324 | 24 | 36 |
| 2 in | 162 | 12 | 18 |
| 3 in | 108 | 8 | 12 |
| 4 in | 81 | 6 | 9 |
How deep to spread mulch
University of Florida IFAS Extension recommends keeping a 2 to 3 inch layer of mulch on plant beds, and leaving at least 2 inches of space around tree trunks to prevent rot. Deeper is not better: piling mulch against trunks and stems keeps the bark wet.
If you are topping up last year’s mulch, measure what is left and add only the difference.
Common questions
How much area does a yard of mulch cover?
108 square feet at 3 inches deep, 162 square feet at 2 inches, or 324 square feet at 1 inch.
How many bags of mulch make a yard?
13.5 bags of 2 cubic feet, or 9 bags of 3 cubic feet. A cubic yard is 27 cubic feet.
How much mulch do I need for 200 square feet?
At 3 inches deep, 200 sq ft needs 50 cubic feet: 1.85 cubic yards, 25 bags of 2 cu ft or 17 bags of 3 cu ft. At 2 inches it needs 1.23 cubic yards, or 17 bags of 2 cu ft.
How much mulch is in a bag?
Most bagged mulch comes in 2 or 3 cubic foot bags; the size is printed on the bag. A 2 cubic foot bag covers 8 square feet at 3 inches deep, and a 3 cubic foot bag covers 12.
How deep should mulch be?
2 to 3 inches for planting beds, the depth UF/IFAS Extension recommends. Keep it at least 2 inches back from tree trunks.
Is bulk mulch cheaper than bags?
Usually, for larger jobs. Compare the price per cubic yard of bulk (plus delivery) with the price of 13.5 bags of 2 cu ft or 9 bags of 3 cu ft.
Sources
- University of Florida IFAS Extension, Florida-Friendly Landscaping: Principle 4, Mulch. 2 to 3 inch layer on plant beds; at least 2 inches of space around tree trunks
See the methodology page for how YardageHQ builds and checks its calculators.