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Garden & landscaping
How much mulch do I need?
Enter your garden bed length, width and target depth and the mulch calculator tells you the volume in cubic yards or the exact number of bags. A 10 × 10 ft bed at the standard 3-inch depth needs 0.93 cubic yards — about 13 bags of the common 2 cu ft size.
Measure each bed in square feet and set your target depth in inches, then let the calculator do the unit juggling: the result comes in cubic yards for bulk deliveries and in bags for the common 1.5 and 2 cu ft retail sizes, whichever your yard or garden center sells. Depth changes volume fast — moving from 2 to 3 inches raises what you need by 50% — so set your budget and thickness before you order.
Frequently asked questions
How many bags of mulch are in a cubic yard?
One cubic yard is 27 cu ft, so a yard equals about 13.5 bags of 2 cu ft mulch — order 14 to be safe. For a 1.5 cu ft bag, a yard is 18 bags.
How deep should mulch be for flower beds?
Use 2–3 inches for established beds — that keeps moisture in and weeds down without smothering plants. New planting areas can take 3–4 inches, but keep mulch away from tree trunks and plant crowns.
Is bulk mulch cheaper than bagged mulch?
Usually yes — bulk mulch runs roughly $20–40 per cubic yard delivered, while the same yard in 2 cu ft bags can cost $60–90. The break-even point is usually around 1–2 cubic yards once you add delivery fees.
How do I measure a round garden bed for mulch?
Measure the diameter, then use the circle formula: area = π × (diameter ÷ 2)². A 10-ft circle is about 78 sq ft, which at 3 inches needs 0.73 cu yd — roughly 10 bags of 2 cu ft mulch.
How many bags of mulch do I need for a 10×10 garden bed?
A 10 × 10 ft bed is 100 sq ft. At the standard 3-inch depth that is 25 cu ft — 0.93 cubic yard — or about 13 bags of 2 cu ft mulch, so buy 14 to cover slight settling.
Which mulch lasts longest — hardwood bark, cedar or rubber?
Plain hardwood bark breaks down in about 1–2 years and enriches the soil. Cedar and cypress last 3–4 years thanks to natural oils that resist insects and decay. Rubber mulch never decomposes but holds heat, costs more and adds nothing to the soil — choose it mainly for playgrounds.
Mulch Calculator
Imperial
ft
ft
inches
Enter your bed size to see the result.
–
bags
Bags always round up. For big beds, bulk delivery is usually cheaper — see the bulk guide below.
How it works
How to use this mulch calculator
1Measure the beds
Measure each bed's length and width in feet. For circle beds, use the diameter in place of both fields — the formula below handles the math.
- Add up rectangular sections of curvy beds separately.
- New beds with freshly planted shrubs can take more mulch.
- Wood chip mulch settles about 20% after rain — depth is measured fresh.
2Pick the depth
Depth is the single biggest driver of volume, so it matters more than the bed area.
- 2 inches: topping up an existing mulch layer.
- 3 inches: the standard fresh layer for flower beds.
- 4+ inches: new planting areas or weed suppression around trees.
- Never mound mulch against tree trunks ("mulch volcano" harms bark).
3Bagged or bulk?
Under about 1 cubic yard, bagged mulch from the garden center is convenient. Above 1–2 yards, bulk delivery in cubic yards is typically 30–50% cheaper and means fewer plastic bags — the calculator shows both numbers so you can compare.
The math
Mulch quantity formula
Cubic feet = length × width × (depth ÷ 12) • Cubic yards = cubic feet ÷ 27
Bags needed = cubic feet ÷ bag size (round up — and buy 1 extra bag for touch-ups)
Worked example — 10 × 10 ft bed at 3 inches with 2 cu ft bags:
Volume: 100 × 0.25 = 25 cu ft = 0.93 cu yd; 25 ÷ 2 = 12.5 → buy 13 bags.
Volume: 100 × 0.25 = 25 cu ft = 0.93 cu yd; 25 ÷ 2 = 12.5 → buy 13 bags.
Buying guide
Bulk vs. bagged mulch comparison
| Bed size | Depth 2 in | Depth 3 in | Cheaper option |
|---|---|---|---|
| 4 × 8 ft | 5 bags / 0.2 yd | 8 bags / 0.3 yd | Bagged |
| 10 × 10 ft | 9 bags / 0.6 yd | 13 bags / 0.9 yd | Bagged or bulk |
| 20 × 20 ft | 34 bags / 2.5 yd | 50 bags / 3.7 yd | Bulk (clearly) |
| 30 × 20 ft | 50 bags / 3.7 yd | 75 bags / 5.6 yd | Bulk |
Bag counts are for 2 cu ft bags, rounded up. One cubic yard = 27 cu ft ≈ 13.5 of the 2 cu ft bags.
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