Landscaping
Mulch Calculator
Find out how much mulch you need for your garden beds. Enter each bed and the depth you want, and this mulch calculator gives the cubic yards for a bulk delivery or the number of 2 cubic foot bags, plus an optional cost so you can compare bulk and bagged mulch.
Result
Enter your measurements and press Calculate. What to buy, the working and the cost will appear here.
How to use the mulch calculator
- Measure each bed. Use a rectangle for straight beds, a circle for tree rings, or enter a known area. Add a row for every bed.
- Set the depth. 2–3 inches suits most beds; use 3–4 inches for paths and play areas.
- Choose the mulch and the bag size you plan to buy (2 ft³ is the most common).
- Add a price per cubic yard or per bag to compare, then press Calculate.
How much mulch do I need?
Mulch is sold by volume, so work out the volume of each bed and add them up:
cubic yards = area (ft²) × depth (in) ÷ 324
2 ft³ bags = cubic yards × 13.5
A 10 ft × 10 ft bed at 3 inches deep is 100 × 3 ÷ 324 = 0.93 cubic yards, or about 13 bags of 2 cubic feet. Add around 10% because fresh mulch settles once it is watered.
Worked example: front beds and a tree ring
A house has a 20 ft × 4 ft front bed, a 12 ft × 3 ft side bed and a 6 ft circle around a tree. All three get 3 inches of shredded hardwood, with 10% allowance for settling, and bags cost $4.50 each:
- Area 1: 20 ft × 4 ft = 80 ft²; × 3 in (0.25 ft) = 20 ft³
- Area 2: 12 ft × 3 ft = 36 ft²; × 3 in (0.25 ft) = 9 ft³
- Area 3: π × (3 ft)² = 28.27 ft²; × 3 in (0.25 ft) = 7.07 ft³
- With allowance: 1.336 yd³ × 1.1 = 1.469 yd³
- Weight: 1.469 yd³ × 0.3 tons/yd³ = 882 lb
- Bags: 39.68 ft³ ÷ 2 ft³ per bag = 20 bags
That is 1.47 yd³ of mulch, or 20 bags of 2 ft³ for about $90.00. Compare that with your landscape yard’s price per cubic yard plus delivery: for jobs over a couple of yards, bulk is usually cheaper. Open this example in the calculator.
Mulch coverage chart
| Depth | One cubic yard covers | One 2 ft³ bag covers |
|---|---|---|
| 1 in | 324 ft² | 24 ft² |
| 2 in | 162 ft² | 12 ft² |
| 3 in | 108 ft² | 8 ft² |
| 4 in | 81 ft² | 6 ft² |
One cubic yard holds 13.5 bags of 2 ft³, 9 bags of 3 ft³ or 18 bags of 1.5 ft³.
How deep should mulch be?
- Flower and shrub beds: 2–3 in. Enough to stop weeds and hold moisture without smothering roots.
- Topping up an existing bed: 1 in is often enough each year, since last year’s mulch is still there.
- Paths and play areas: 3–4 in of coarse mulch or wood chips for a softer, longer-lasting surface.
- Around trees: 2–3 in in a wide ring, but keep mulch a few inches away from the trunk. Piled-up “mulch volcanoes” trap moisture against the bark.
Types of mulch
| Mulch | Typical weight per yd³ | Notes |
|---|---|---|
| Shredded hardwood | 600 lb | The most common bed mulch; it knits together and settles over the first few weeks. |
| Pine bark nuggets | 500 lb | Chunky and slow to break down; light pieces can float away in heavy rain. |
| Dyed wood mulch (black, brown, red) | 600 lb | Colored recycled wood; holds its color for a season or so. |
| Wood chips (arborist) | 500 lb | Coarse mixed chips, often cheap or free from tree services; good for paths. |
Weight only matters for hauling: a cubic yard of wet mulch can weigh far more than a dry one, but it covers the same area.
Bulk or bagged mulch?
- Bags are clean, easy to carry and good for small beds or top-ups. They cost more per cubic yard.
- Bulk is sold by the cubic yard and is usually much cheaper for two yards or more. Many yards deliver for a fee, or will load a pickup (a full-size bed holds roughly 2 cubic yards of mulch).
- Order a little extra rather than run short; a spare pile is easy to use for top-ups.
Assumptions and limitations
- Beds are treated as flat with an even depth. Sloped beds need slightly more.
- The settling allowance is added to the volume; fresh mulch can settle more after heavy rain.
- Weights are typical moist values for hauling only; mulch is priced by volume.
Mulch questions
How many bags of mulch are in a yard?
13.5 bags of 2 cubic feet, because a cubic yard is 27 cubic feet. That is 9 bags of 3 ft³ or 18 bags of 1.5 ft³.
How much area does a yard of mulch cover?
About 162 ft² at 2 inches deep, 108 ft² at 3 inches and 81 ft² at 4 inches.
How many bags of mulch do I need for a 10 × 10 bed?
At 3 inches deep, 100 ft² needs 25 ft³ of mulch, so 13 bags of 2 ft³, or 14 with a little extra for settling.
Should I remove old mulch before adding new?
Not usually. If the old layer has broken down, rake it loose and add an inch or two on top. If it is already 3 inches or more, remove some so the total stays around 2–3 inches.
Formulas, unit conversions and default values are explained on our methodology page. Results are estimates; check manufacturer data and local codes before you buy or build.