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How much mulch do I need? Bags and cubic yards by area

Mulch is area times depth: 300 square feet of beds mulched 3 inches deep is 79 cubic feet with 5% extra, which is 2.9 cubic yards, 40 bags of 2 cubic feet or 27 bags of 3 cubic feet. A cubic yard covers 108 square feet at 3 inches and is 14 bags of 2 cubic feet, so above about half a yard a bulk delivery is cheaper. The tables run from 100 to 1,000 square feet at 2, 3 and 4 inches.

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Mulch by area and depth

The tables add 5% for settling and for beds that are never quite the size you measured. Bags are the two common sizes; for bulk, order cubic yards. Mulch is sold by volume, so the calculator's weight figure is not needed here: a yard of dry bark weighs a fraction of a yard of gravel and a lot more when it is wet.

2 inch layer, 5% extra
AreaCubic feetCubic yardsBags (2 cu ft)Bags (3 cu ft)
100 sq ft180.6596
200 sq ft351.31812
300 sq ft531.942718
500 sq ft883.244430
1,000 sq ft1756.488859
3 inch layer, 5% extra
AreaCubic feetCubic yardsBags (2 cu ft)Bags (3 cu ft)
100 sq ft260.97149
200 sq ft531.942718
300 sq ft792.924027
500 sq ft1314.866644
1,000 sq ft2639.7213288
4 inch layer, 5% extra
AreaCubic feetCubic yardsBags (2 cu ft)Bags (3 cu ft)
100 sq ft351.31812
200 sq ft702.593524
300 sq ft1053.895335
500 sq ft1756.488859
1,000 sq ft35012.96175117

How the numbers are worked out

Square feet x depth in feet = cubic feet: 300 x 0.25 = 75 cubic feet at 3 inches, 79 with 5%. Divide by 27 for cubic yards, or by 2 or 3 for bags, and round up. The gravel and soil calculator does the same for any area, depth and bag size. Measure beds as rectangles and add them; a circular bed is 3.14 x radius².

Bags or bulk?

A cubic yard is 14 bags of 2 cubic feet, so 100 square feet at 3 inches is already 14 bags. Bags make sense for a couple of small beds or a colour you cannot get in bulk; from about half a yard up, a delivered yard is cheaper and it arrives as one pile, not a car full of plastic. Bulk mulch is measured loose in the truck, so the 5% is worth keeping.

Metric: cubic metres and 50 L bags

Bark and wood chip are sold in 50 and 70 litre bags or by the cubic metre (about 1.3 cubic yards). Five centimetres is the usual depth, 7.5 for weed suppression.

Metric beds, 5% extra
AreaDepthCubic metres50 L bags70 L bags
10 m²5 cm0.53118
25 m²5 cm1.312719
50 m²5 cm2.635338
100 m²5 cm5.2510575
10 m²7.5 cm0.791612
25 m²7.5 cm1.974029
50 m²7.5 cm3.947957
100 m²7.5 cm7.88158113

Before you order

  • Pull the old mulch back and check its depth first; topping up 1 inch uses a third of what a new 3 inch bed does.
  • Edging the bed and laying the mulch to the edge is what stops it migrating onto the lawn; a lip of 2 inches at the edge is enough.
  • Gravel or stone as a decorative mulch is worked out the same way, but by weight: see the cubic yard weight guide. Topsoil under the mulch is in the topsoil guide.

Frequently asked questions

How much mulch do I need for 100 square feet?
0.65 cubic yards at 2 inches, 0.97 at 3 inches and 1.3 at 4 inches, with 5% extra. In bags of 2 cubic feet that is 9, 14 and 18; in 3 cubic feet bags 6, 9 and 12.
How much mulch do I need for 500 square feet?
4.9 cubic yards at the usual 3 inches, or 66 bags of 2 cubic feet. That is a bulk delivery: a full-size pickup carries about 2 to 3 cubic yards of mulch, which is far less weight than the same volume of gravel.
How many bags of mulch make a cubic yard?
14 bags of 2 cubic feet or 9 bags of 3 cubic feet, because a yard is 27 cubic feet (13.5 and 9 exactly). Compare the price of those bags with a delivered yard before you load the car; bulk usually wins from half a yard up.
How deep should mulch be?
2 to 3 inches on established beds and around shrubs, 3 to 4 inches for weed suppression on bare ground or paths. Deeper than 4 inches keeps water and air out of the soil and encourages rot at the base of plants. Keep it an inch or two away from stems and trunks.
How much mulch do I need to prevent weeds?
3 to 4 inches, on top of the soil or a permeable weed membrane, so 6.5 cubic yards for 500 square feet at 4 inches. Thinner layers let light through and weeds come up; refresh the top inch every year or two as it breaks down.
How many square feet does a yard of mulch cover?
162 square feet at 2 inches, 108 at 3 inches and 81 at 4 inches, before any extra. A 2 cubic feet bag covers 12, 8 and 6 square feet at the same depths.

Last updated 2026-09-12. Figures are planning estimates from typical product data: check the yield, size or coverage printed on what you buy and round up.