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Mulch Calculator

Measure the bed and depth; get the yards or bags of mulch.

Sources checked 9 November 2026

Rectangle 24′ 0″ × 6′ 0″, 3″ deep, 10% extra

144 sq ft24′ 0″6′ 0″3″
24′ 0″6′ 0″3″
Fig. 1 The example rectangle, drawn to scale at its depth. Top area 144 sq ft. The circle shows the depth at about 7× size. The circle shows the depth at about 8× size.

Example: rectangle 24′ 0″ × 6′ 0″, 3″ deep. Type your sizes

1.47cubic yardswith 10% extra

Before the extra: 36.00 cu ft = 1.33 cu yd

2 cu ft bags
19.8 20
40 cu ft in all
1.50 cu ft bags
26.4 27
40.5 cu ft in all

Fig. 2 The bags stacked four to a layer, each bag drawn by its volume.

Your own sizes need scripts turned on. Without them the page shows the worked example.

Filled in with an example. Type your sizes over it.

Length

Width

Depth

Illinois Extension: mulch in beds and tree rings 2 to 4 in.

Extra to order

A landscape supplier’s rule: about 10% for mulch, which settles

To order

Rectangle 24′ 0″ × 6′ 0″, 3″ deep: 1.47 cu yd with 10% extra. Buy one row: bulk, or one bag size.

ItemCountNote
Volume1.33 cu yd36.00 cu ft, before the extra.
Extra+0.13 cu yd10% on its own line.
Bulk1.47 1.5 cu ydWith 10% extra, rounded up to the next half yard.
Bags of 2 cu ft19.8 2040 cu ft in all.
Bags of 1.5 cu ft26.4 2740.5 cu ft in all.

How much mulch do I need

To work out the amount of mulch you need, multiply the length and width of the bed in feet by the depth in feet (inches ÷ 12) for cubic feet, divide by 27 for cubic yards, and add the extra. A 24 × 6 ft mulch bed, 3 in deep is 36 cubic feet, or 1.33 cubic yards; with 10% extra, 1.47 cubic yards, which is 1.5 cubic yards in half yards or 20 bags of 2 cubic feet.

Beds come in every shape, so each piece in the calculator has its own: a circle for a tree ring, a ring around a trunk, a border along a path. Take a piece away for a shrub or a stepping-stone area.

  1. Read the tape into feet

    24′ 0″ = 24 ft. 6′ 0″ = 6 ft. 3″ = 3 ÷ 12 = 0.250 ft.

  2. Area times depth for each piece

    • 24.00 × 6.00 = 144.00 sq ft; × 0.250 ft deep = 36.00 cu ft

  3. Divide by 27 for cubic yards

    36.00 ÷ 27 = 1.33 cu yd

  4. Add the extra

    1.33 × 1.10 = 1.47 cu yd. That is the number to order.

  5. Bags: divide by the bag size, round up

    39.60 cu ft (with 10% extra) ÷ 2 = 19.8, so 20 bags of 2 cu ft.

Cubic yards = length × width × depth ÷ 27 × (1 + extra)

24.00 × 6.00 × 0.250 = 36.00 cu ft; ÷ 27 = 1.33 cu yd; × 1.10 = 1.47 cu yd

All sizes in feet.

Mulch in cubic yards and bags: how many bags in a yard

A cubic yard is 13.5 bags of 2 cubic feet or 18 bags of 1.5 cubic feet. Bagged mulch is sold by volume: each mulch bag gives its size in cubic feet. A cubic yard is 27 cubic feet, so divide 27 by the bag in cubic feet and round up for the bags needed.

Bag sizeBags per cu yd
2 cu ft13.5
1.5 cu ft18

Worked out: 27 cu ft ÷ the bag size. Round up when you buy. Sizes as sold: Scotts Nature Scapes Color Enhanced Mulch, Miracle-Gro Garden Soil All Purpose.

Bulk yards sell by the whole or half yard, and some deliver only from 1 or 3 cubic yards up.

How much a cubic yard of mulch covers

A cubic yard covers 162 square feet at 2 inches, 108 square feet at 3 inches and 81 square feet at 4 inches. 1,000 square feet at 3 inches takes 9.26 cubic yards.

DepthSq ft per cu yd
1 in324
2 in162
3 in108
4 in81
6 in54
12 in27

Worked out: 27 cu ft ÷ (depth in inches ÷ 12).

Area2 in deep3 in deep4 in deep6 in deep
100 sq ft0.620.931.231.85
200 sq ft1.231.852.473.7
500 sq ft3.094.636.179.26
1,000 sq ft6.179.2612.3518.52

Worked out: area × depth in feet ÷ 27, no extra added.

How deep to spread mulch

The depth sets the order more than anything else; the extension services in the table agree on a few inches in a bed, a little less once it has settled. Under play equipment the federal handbook asks for 9 inches to stay, so 12 inches goes down.

JobDepthWho says so
Mulch in beds and tree rings2 to 4 inIllinois Extension
Mulch, once settled2 to 3 inIllinois Extension
Playground wood chips or mulch9 in kept; place 12 inU.S. CPSC

From each guide as written: University of Illinois Extension, U.S. Consumer Product Safety Commission.

Mulch settles and breaks down: in a UF/IFAS trial, bark mulch laid 9 cm deep was 6 cm after 2 years. That is why the calculator adds 10% extra; one supplier advises about 10%.

Mulch calculator FAQ

How many bags of mulch do I need?

Cubic feet of the bed ÷ the bag size, rounded up. The example takes 20 bags of 2 cubic feet or 27 of 1.5 cubic feet.

How much does a yard of mulch weigh?

We found no published figure we can stand behind; it varies with the wood and the rain. Mulch is sold by volume, so the order here is in yards and bags.

How many square feet does 1 yard of mulch cover?

108 square feet at 3 inches deep.

Sources

Depths, bag sizes, settling and supplier advice on this page come from these documents, checked 9 November 2026.

  1. NIST Handbook 44 (2025), Appendices B and C, Units of Measurement
  2. University of Illinois Extension, Proper Mulching Techniques
  3. University of Illinois Extension, Mulch Madness, July 2017
  4. U.S. Consumer Product Safety Commission, Public Playground Safety Handbook, Pub. 325
  5. UF/IFAS Extension, FOR 69, Landscape Mulches: How quickly do they settle?
  6. Bulk Direct Landscape Supply, How Much Mulch Do I Need?, March 2025
  7. Heritage Landscape Supply Group, bulk mulch page, Mid-Atlantic
  8. Mulch Mound, delivery policy
  9. Scotts Nature Scapes Color Enhanced Mulch product page
  10. Miracle-Gro Garden Soil All Purpose product page