Mulch Calculator

US & Canada

Measure the bed, pick a depth, and get the answer in cubic yards, cubic metres and bags, including the litre-labelled bags sold in Canada.

Work out your mulch

ft
ft
in
%

Mulch needed

0 cubic yards

Or buy bags

Bag Bags Sold in

How much mulch you need, in one line

Mulch is sold by volume, so the sum is always the same: area × depth. The only trick is keeping your units straight, because the depth is in inches while everything else is in feet.

  • Cubic feet = area (sq ft) × depth (inches) ÷ 12
  • Cubic yards = cubic feet ÷ 27
  • Bags of 2 cu ft = cubic feet ÷ 2

How far one cubic yard goes

These are exact, not estimates. A cubic yard is 27 cubic feet, so the coverage falls straight out of the depth.

Area covered by one cubic yard of mulch, by depth
Depth Covers In metric Use it for
2" 162 sq ft 15.1 m² Topping up an existing bed
3" 108 sq ft 10 m² Standard for a new bed
4" 81 sq ft 7.5 m² Suppressing weeds

Bags per cubic yard

Bags needed to make up one cubic yard of mulch
Bag Cubic feet Per cubic yard Sold in
2 cu ft 2 13.5 Both
3 cu ft 3 9 US
56 L 1.978 13.7 Canada
85 L 3.002 9 Canada

Buying in Canada? The same bag is usually labelled in litres rather than cubic feet. A 56 L bag is the 2 cu ft bag, and 85 L is the 3 cu ft bag, so the counts above still apply.

Mulch for common bed sizes

Mulch needed for common bed areas and depths
Area Depth Cubic yards Cubic metres 2 cu ft bags 3 cu ft bags
100 sq ft 2" 0.62 0.47 9 6
100 sq ft 3" 0.93 0.71 13 9
100 sq ft 4" 1.23 0.94 17 12
200 sq ft 2" 1.23 0.94 17 12
200 sq ft 3" 1.85 1.42 25 17
200 sq ft 4" 2.47 1.89 34 23
300 sq ft 2" 1.85 1.42 25 17
300 sq ft 3" 2.78 2.12 38 25
300 sq ft 4" 3.7 2.83 50 34
400 sq ft 2" 2.47 1.89 34 23
400 sq ft 3" 3.7 2.83 50 34
400 sq ft 4" 4.94 3.78 67 45
500 sq ft 2" 3.09 2.36 42 28
500 sq ft 3" 4.63 3.54 63 42
500 sq ft 4" 6.17 4.72 84 56
1000 sq ft 2" 6.17 4.72 84 56
1000 sq ft 3" 9.26 7.08 125 84
1000 sq ft 4" 12.35 9.44 167 112

Before you order

  • Keep it off the trunks. Mulch piled against bark holds moisture against it and invites rot and rodents. Leave a gap.
  • Top up rather than rebuild. Most beds only need an inch or so a year once they are established. Measure what is already there.
  • Bulk is sold by the yard, bags by the cubic foot. Mixing the two up by a factor of 27 is the classic over-order.
  • Fresh wood chips can rob nitrogen from the top inch of soil as they break down. That matters for vegetable beds more than shrubs.

Common questions

How many bags of mulch are in a cubic yard?
A cubic yard is 27 cubic feet, so it takes 13.5 bags of 2 cu ft or 9 bags of 3 cu ft. Since you cannot buy half a bag, that is 14 of the 2 cu ft bags in practice. This is the single most useful number in mulch buying, because it tells you whether bulk delivery is worth it.
How much mulch do I need for 500 square feet?
At the standard 3 inches deep, 500 sq ft needs 4.63 cubic yards (3.54 m³), which is about 63 bags of 2 cu ft. At 2 inches it is a third less; at 4 inches, a third more. Depth changes the answer more than most people expect.
How much mulch do I need for 100 square feet?
At 3 inches deep, 100 sq ft needs 0.93 cubic yards (25 cubic feet), which is 13 bags of 2 cu ft. One cubic yard covers 108 sq ft at that depth.
How deep should mulch be?
2 to 3 inches for most beds, and 3 to 4 inches if you are trying to suppress weeds. Deeper is not better. More than about 4 inches can stop water and air reaching the roots, and piling mulch against trunks or stems invites rot and pests. Leave a few inches of bare ground around the base of anything woody.
How much mulch do I need to prevent weeds?
Aim for 3 to 4 inches. Below about 2 inches, light gets through and weed seeds germinate happily. Mulch suppresses weeds by blocking light, so an even depth matters more than the type you buy. It will not stop established perennial weeds, so pull those first.
How many bags of mulch are on a pallet?
Typically 65 to 70 bags of 2 cu ft, which works out at roughly 5 cubic yards. Counts vary by brand and retailer though, so confirm before you plan a delivery or a trailer load.
Is it cheaper to buy mulch in bags or in bulk?
Bulk is usually cheaper per yard once you need more than about 10 bags, which is well under a cubic yard. The catch is delivery: you need somewhere to tip it and the willingness to barrow it around. Bags win for small beds, awkward access, or when you want to do the job over several weekends.
How do I work out mulch for a circle around a tree?
Switch the calculator to Ring / border, put the full width of the mulched circle as the outer diameter and the trunk or planting hole as the inner one. That subtracts the middle instead of making you buy mulch for ground you are not covering. Keep the mulch pulled back from the trunk itself.