Mulch is sold two ways: in bags of 2 or 3 cubic feet at garden centers, and by the cubic yard from landscape suppliers. This calculator takes the size of your bed and the depth you want, and tells you both — so you can compare the price of bags against a bulk delivery.
How to use the mulch calculator
- Choose the bed shape. Rectangle for most beds, circle for rings around trees, or enter a known area if you have already added up several beds.
- Enter the size. For an irregular bed, measure its longest length and its average width — close enough for mulch.
- Choose the depth. 3 inches is a good default for new beds; top-ups over existing mulch need only 1–2 inches.
Mulch formula
Cubic yards = cubic feet ÷ 27
Bags = ⌈ cubic feet ÷ bag size ⌉
Shortcut: at 3 inches deep, every 100 sq ft needs 25 cu ft, a little under one cubic yard.
Worked example: a 20 × 10 ft front bed
- Area: 20 × 10 = 200 sq ft
- Volume at 3 in: 200 × 3 ÷ 12 = 50 cu ft
- Cubic yards: 50 ÷ 27 = 1.85 cu yd
- Bags: 50 ÷ 2 = 25 bags of 2 cu ft, or 50 ÷ 3 = 16.7 → 17 bags of 3 cu ft
Mulch needed by area and depth
| Area | Depth | Cubic yards | 2 cu ft bags | 3 cu ft bags |
|---|---|---|---|---|
| 50 sq ft | 3 in | 0.46 | 7 | 5 |
| 100 sq ft | 2 in | 0.62 | 9 | 6 |
| 100 sq ft | 3 in | 0.93 | 13 | 9 |
| 200 sq ft | 3 in | 1.85 | 25 | 17 |
| 200 sq ft | 4 in | 2.47 | 34 | 23 |
| 500 sq ft | 3 in | 4.63 | 63 | 42 |
| 1,000 sq ft | 2 in | 6.17 | 84 | 56 |
| 1,000 sq ft | 3 in | 9.26 | 125 | 84 |
How much area one cubic yard covers
| Depth | Coverage per cubic yard |
|---|---|
| 1 in | 324 sq ft |
| 2 in | 162 sq ft |
| 3 in | 108 sq ft |
| 4 in | 81 sq ft |
Mulching tips
- Don't build “mulch volcanoes.” Leave a gap of a few inches around tree trunks and plant stems.
- Weed and water first. Mulch holds moisture in and keeps light out — it works best on clean, damp soil.
- Top up, don't pile up. Check the existing depth before adding more; old mulch breaks down over a season or two.
- Bulk is measured loosely. Mulch settles after spreading, so a slightly generous order is normal.
Spreading stone instead? The Gravel Calculator converts to tons. For soil, compost or any other bulk material, use the Cubic Yard Calculator.
Frequently asked questions
How many bags of mulch are in a yard?
One cubic yard is 27 cubic feet, so it equals 13.5 bags of 2 cu ft mulch or 9 bags of 3 cu ft mulch.
How deep should mulch be?
2 to 3 inches is the usual recommendation for garden beds; up to 4 inches helps suppress weeds in open areas. Keep mulch a few inches away from tree trunks and plant stems — piling it against bark invites rot and pests.
How much area does a yard of mulch cover?
At 3 inches deep, one cubic yard covers 108 sq ft. At 2 inches it covers 162 sq ft, and at 4 inches 81 sq ft. Divide 324 by the depth in inches to get the coverage in square feet.
Is bagged or bulk mulch cheaper?
For more than a couple of cubic yards, bulk mulch from a landscape supplier is often cheaper per yard, but delivery fees apply. Bags are easier for small jobs and tight spaces. Compare the per-cubic-yard price either way.
How much mulch for a tree ring?
Measure the diameter and choose the circle shape. A 6 ft ring 3 inches deep holds about 7 cu ft — four 2 cu ft bags.