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Mulch calculator

Enter the size of each garden bed and how deep you want the mulch, usually 2 to 3 inches. You get the total in cubic yards for bulk delivery, or the number of 2 or 3 cubic foot bags to pick up.

Units
Bag size
Typical depth
  1. Shape
Extra for settling and uneven beds

Fresh mulch settles a little, and beds are rarely perfectly flat.

Mulch to buy
0.78 cubic yardsor 11 bags of 2 cu ft
21 cu ft · 0.59 m³, with 5% extra

Bags of mulch

1.5 cu ft bags
14
2 cu ft bags
11
3 cu ft bags
7

At 3 in deep, one 2 cu ft bag covers about 8 sq ft. Bag sizes are printed on the front: check yours.

Amounts

Exact volume (no extra)
0.74 cu yd
Cubic yards
0.78
Cubic feet
21
Cubic meters
0.59
Bulk order, to the next ½ yard
1 cu yd
Area covered
80 sq ft

Many landscape yards load bulk material by the half or whole yard.

  • Nothing is uploaded
  • Free, no sign-up
  • Works on phone and desktop

How to work out how much mulch you need

  1. 1

    Measure each bed and pick its shape: a rectangle, a circle for tree rings, or a triangle for corners. Add as many beds as you have.

  2. 2

    Choose a depth. 2 to 3 inches suits most beds; 1 inch refreshes last year's mulch.

  3. 3

    Pick the bag size on the shelf, usually 2 cu ft, and keep a little extra for settling.

  4. 4

    Read the cubic yards for bulk delivery and the number of bags. Add both prices to see which costs less.

Features

  • Every bed at once

    Add borders, island beds, tree rings and corner beds, each with its own shape and depth, for one total.

  • Bags of 1.5, 2 and 3 cu ft

    See the count for each common bag size side by side, rounded up to whole bags.

  • Bulk cubic yards

    Get the volume in cubic yards for a delivery, plus cubic feet and cubic meters.

  • Bags or bulk?

    Enter a bag price and a bulk price per yard to see which is cheaper for your beds.

Mulch coverage chart

The thinner you spread it, the further mulch goes. One cubic yard covers 324 square feet at 1 inch deep, and the area halves each time the depth doubles. Here is what a yard and the two most common bag sizes cover:

Depth1 cubic yard coversOne bag covers
1 in324 sq ft24 sq ft (2 cu ft) · 36 sq ft (3 cu ft)
2 in162 sq ft12 sq ft (2 cu ft) · 18 sq ft (3 cu ft)
3 in108 sq ft8 sq ft (2 cu ft) · 12 sq ft (3 cu ft)
4 in81 sq ft6 sq ft (2 cu ft) · 9 sq ft (3 cu ft)

Worked examples

  • A border 20 ft long and 4 ft deep, at 3 inches: 20 cubic feet. With 5% extra that's 21cubic feet: 11 bags of 2 cu ft or 7 bags of 3 cu ft.
  • A tree ring 6 ft across, at 3 inches: 7.1 cubic feet, or 4 bags of 2 cu ft. Choose Circle and enter the diameter. The trunk takes up so little room that you can ignore it.
  • All the front beds, 50 × 6 ft at 3 inches: 75 cubic feet, or 2.78 cubic yards. That's 38 bags of 2 cu ft, the point where a bulk delivery starts to make sense.

Bags or bulk?

Bagged mulch is easy to buy a little at a time, stays tidy in the car and stores well. Bulk mulch is sold by the cubic yard, scooped into a truck or delivered and tipped on your drive, and there are 13.5 two-cubic-foot bags in every yard. For a few beds, bags are simpler. Once you need two or three yards, bulk usually means far less carrying, and often a lower price per yard even after delivery. Put your local prices into the calculator to compare.

Bag sizes are printed on the front of the bag in cubic feet. Mulch is often sold damp, and a soaked bag can weigh a lot more than a dry one, but the volume on the label is what counts.

Depth for each kind of bed

  • Annual and perennial beds: about 2 inches of a fine mulch, kept back from the crowns of plants.
  • Shrub borders: 2 to 3 inches of shredded bark or chips.
  • Trees: 2 to 3 inches in a wide ring, a few inches clear of the trunk. Wider is better than deeper.
  • Top-ups: mulch breaks down over a season or two. Rake it, measure what's left, and add about 1 inch.
  • Play areas: at least 9 inches of wood mulch or chips under equipment, put down at about 12 inches (CPSC guidance).

Caring for mulched beds

Weed and water before you mulch, because a layer of mulch holds in whatever is underneath, moisture and weeds alike. Spring, once the soil has warmed, is the usual time to add mulch; a fall layer helps protect roots through winter. Keep mulch off stems and trunks, and pull it back from the house foundation and siding. Leave a clean edge along lawns and paths so it doesn't wash out in heavy rain.

Edging a bed with stone? The gravel calculator works out pea gravel and river rock in tons. Starting a new bed? The topsoil calculator covers garden soil and settling. For odd-shaped beds, measure the area with the square footage calculator, or check any volume in the cubic yard calculator.

Frequently asked questions

How much mulch do I need?

Multiply the bed's square feet by the depth in inches and divide by 324 to get cubic yards. A 20 × 4 ft border is 80 sq ft; at 3 inches that's 20 cubic feet, or 0.74 cubic yards: 10 bags of 2 cu ft.

How many bags of mulch are in a yard?

A cubic yard is 27 cubic feet, so it takes 13.5 bags of 2 cu ft (14 in practice), 9 bags of 3 cu ft or 18 bags of 1.5 cu ft.

How much does a bag of mulch cover?

A 2 cu ft bag covers about 12 sq ft at 2 inches deep, 8 sq ft at 3 inches and 24 sq ft at 1 inch. A 3 cu ft bag covers half as much again.

How deep should mulch be?

University extension services generally recommend 2 to 3 inches. Finer mulches work at the low end and coarse bark or wood chips at the high end. More than about 4 inches can keep water and air from reaching roots.

How do I mulch around a tree?

Spread a wide, flat ring rather than a mound. A common guide is the 3-3-3 rule: keep mulch about 3 inches from the trunk, no more than 3 inches deep, in a ring at least 3 feet across. Mulch piled against the bark, the so-called mulch volcano, holds moisture against it and invites rot.

Should I remove old mulch before adding new?

Usually not. Rake the old layer to loosen it and check how deep it is: if 2 inches or more remains, a 1-inch top-up is enough. Remove it where it has built up too deep, matted into a crust, or is piled against stems.

How much mulch does a playground need?

The US Consumer Product Safety Commission recommends at least 9 inches of loose-fill such as wood mulch or chips under play equipment. Loose fill packs down, so about 12 inches is usually put down. Use the Playground 12″ preset.

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