Free mulch calculator — cubic yards, weight and cost
Measure your beds, set a depth, and get cubic yards, bag count and cost. Add as many beds as you like — rectangles, circles and triangles — because almost nobody has one rectangular bed.
How deep should mulch go?
Three inches is the number that matters. Below two inches mulch does not suppress weeds — light still reaches the soil and you have essentially paid for decoration. Above four inches you start causing problems: water struggles to reach roots, and mulch piled against trunks and stems holds moisture where it causes rot.
Practical guidance: 3" for established beds, 2" for annual beds you replant often, and 4" only where you are fighting persistent weeds in a bed with mature shrubs. Never volcano it up a tree trunk — pull it back a few inches from the base.
Topping up an existing bed? Measure what is already there and only add the difference. Most beds need about an inch a year once established, not a fresh three.
Coverage at a glance
How far one cubic yard goes, and what 1,000 square feet takes, at each common depth:
| Depth | One cubic yard covers | 1,000 sq ft needs |
|---|---|---|
| 1" | 324 sq ft | 3.1 cu yd |
| 2" | 162 sq ft | 6.2 cu yd |
| 3" | 108 sq ft | 9.3 cu yd |
| 4" | 81 sq ft | 12.3 cu yd |
| 6" | 54 sq ft | 18.5 cu yd |
Weight and delivery
Mulch is light — around 0.35 tons per cubic yard dry, but wood soaks up water and a wet yard can weigh close to double that. That matters if you are hauling it yourself.
Before you order, check access. Bulk material is tipped, not carried — the truck needs room to back in and raise its bed, and most suppliers will not tip on a surface they might damage. Ask about the delivery fee and the minimum order separately, because both change the maths on small jobs.
Turn it into a quote
Hit Copy order and the whole breakdown goes to your clipboard, ready to paste into an estimate. Add your labour, price it with the profit margin calculator, and send it with the estimate generator.
Related: cubic yard calculator, gravel, topsoil, mulch and concrete calculators, plus state-by-state rate data for what landscapers and contractors earn.
FAQ
How much mulch do I need?
Multiply the bed area in square feet by the depth in feet, then divide by 27 for cubic yards. At the standard 3-inch depth, one cubic yard covers 108 square feet. So a 500 square foot bed at 3 inches needs about 4.6 cubic yards.
How many bags of mulch are in a cubic yard?
Thirteen and a half. Bagged mulch is normally sold in 2 cubic foot bags, and a cubic yard is 27 cubic feet, so 27 ÷ 2 = 13.5 bags. Round up to 14 in practice.
Is bulk mulch cheaper than bagged?
Almost always, above about one cubic yard. Bagged mulch typically works out two to three times the price per cubic yard, but bulk carries a delivery fee and often a minimum order. Under a yard, bags usually win once delivery is priced in.
How much does a yard of mulch weigh?
Roughly 400 to 800 pounds dry, so about 0.2 to 0.4 tons. Wet mulch can weigh considerably more. A half-ton pickup can usually take two yards of dry mulch but you should check your payload rating before loading wet material.
How often should I replace mulch?
Top up annually rather than replacing. Organic mulch breaks down and feeds the soil, which is a feature — you are typically adding an inch a year to maintain a three-inch bed. Full replacement is only needed if the mulch has matted or gone sour.