算BuildCalc Get a quote

Mulch Calculator

Area and depth to cubic yards and bags.

Also known as mulch volume · bark mulch · mulch coverage

Quick answer

With the default inputs: Bed area 300 ft² · Spread depth 3 in · Waste 5%Mulch required 2.92 yd³

Use your own dimensions ↓

Inputs

ft²
in
%

Result

Mulch required
2.92yd³
Cubic feet78.8ft³
Bags of 2 ft³40
Bags of 3 ft³27
Coverage per yard108ft²
Pickup loads at 2 yd³1.5loads
How this is worked out

Volume is area x depth/12, divided by 27 for cubic yards. Depth is the variable that matters: 3 in suppresses weeds and holds moisture, under 2 in barely works, and over 4 in starves the soil of air so roots grow up into the mulch and die in the first dry spell. Do not cone mulch up against the trunk - it is common practice and it rots the bark. Keep 2-3 in clear of the trunk and spread it as a ring. Bag versus bulk pricing diverges sharply: bags commonly cost two to three times as much for the same volume, so above 2 yards order bulk.

Next up: Backfill Volume Calculator · Earthwork Calculator

Formula

Volume (ft³) = area × depth(in)/12
Cubic yards = volume ÷ 271 yard = 27 ft³
Bags = volume ÷ 2 (2 ft³ bags)
300 ft² of beds at 3 in with 5% waste: 300 × 0.25 × 1.05 = 78.8 ft³ = 2.92 cubic yards, or 40 bags of 2 ft³. Ordering 3 yards costs less than half of buying those 40 bags.

How to work it out

  1. Measure the bed area, breaking irregular shapes into rectangles - far closer than estimating.
  2. Use 3 in as the general optimum, and only 1-2 in as a top-up over existing mulch.
  3. Volume = area x depth/12, divided by 27 for cubic yards.
  4. For bags divide by 2 (2 ft³ bags), but above 2 yards bulk costs about half.
  5. Keep mulch 2-3 in clear of tree trunks rather than coning it up against them.

Where it goes wrong

Material and cost

Bulk mulch runs USD 25-45 per yard for bark and woodchip, and coloured mulch 40-70. Bagged 2 ft³ is 3-5 a bag, which works out at 40-70 per yard - so above 2 yards order bulk without thinking about it. Delivery is 50-150; collecting it yourself saves that if you can carry it.

On site

Basis

FAQ

What depth should I use?
3 in is the general optimum: enough to block light and hold moisture without starving roots of air. Over existing mulch, top up 1-2 in to reach 3 in overall rather than adding another 3 in each year - it builds up into a water-shedding crust.
Bags or bulk?
Under 1 yard bags are convenient; above 2 yards bulk is far cheaper, often half the unit price. Bulk needs somewhere for the truck to tip - a long enough drive and firm ground, because barrowing it from a distance wrecks your day. A middle option: many yards will load a half yard into a pickup.
Does mulch attract termites?
Bark and woodchip do not in themselves. What attracts them is mulch piled high against the house wall and staying wet, so keep a 6 in clear strip at the foundation exposing it. Fresh mulch also ties up nitrogen at the surface while it breaks down, so fertilise beneath it or use well-rotted compost instead.

Cite this page

Use this format in reports, method statements or coursework. The link is permanent.

Building Calculator. Mulch Calculator. 2026-10-25. https://jianzhujisuan.com/en/mulch-yardage

Results are estimating aids only and are not a design basis. Construction and final accounts must follow the drawings, the applicable standards and an approved method statement. Anything affecting structural safety, shoring or falsework must be checked by a suitably qualified engineer.