Mulch Calculator
Calculate how many cubic yards or bags of mulch you need for any area.
The Formula
1 cubic yard covers 324 ft² at 1 inch deep
= 20 × 8 × 3 / 324
= 480 / 324
= 1.48 yd³ → order 1.5 yd³
How Much Mulch Do You Need?
The recommended depth for mulch is 2–4 inches. Volume (cubic yards) = (Length × Width × Depth in inches) ÷ 324. One cubic yard covers 162 sq ft at 2 inches deep, 108 sq ft at 3 inches, or 81 sq ft at 4 inches.
Mulch Tips
Don't pile mulch against tree trunks ("volcano mulching") — it promotes rot and disease. Keep mulch 2–3 inches away from trunks. A 2–3 inch layer suppresses weeds effectively; more than 4 inches can prevent water and air from reaching roots.
Frequently Asked Questions
How many bags of mulch equal a cubic yard?
Most bagged mulch comes in 2-cubic-foot bags. There are 27 cubic feet in a cubic yard, so approximately 13.5 bags equal one cubic yard. Round up to 14 bags. Bulk mulch delivered by the yard is almost always more economical for areas over about 200 square feet.
How often should I replace mulch?
Organic mulches like wood chips, shredded bark, and straw decompose over time. Top up or replace them annually in spring, adding 1–2 fresh inches over the previous layer. By the time you are ready to remulch, last year's decomposed mulch has become beneficial organic matter in the soil — no need to remove it. Inorganic mulches like rubber or gravel last much longer but do not improve soil quality.
What type of mulch is best?
Shredded hardwood bark and wood chips are the most popular choices — they look natural, decompose slowly, and improve soil over time. Pine bark nuggets are attractive but float during heavy rain. Straw works well in vegetable gardens. Rubber mulch lasts longest but does not improve soil and can retain heat. For pathways, pea gravel or river rock look clean and permanent. Match the mulch to the application.
Does mulch attract termites?
Organic mulch can create a moist environment that some insects find attractive, but properly applied mulch does not cause termite infestations. Keep mulch 6–12 inches away from your home's foundation to reduce any risk. Cedar and cypress mulches have natural oils that are somewhat repellent to insects. If you have had termite issues, use inorganic mulch (gravel, rubber) near the foundation.
Can I use wood chips from tree trimming as mulch?
Yes — fresh wood chips from tree trimming are excellent mulch for paths and around established trees and shrubs. Avoid using them in flower beds or vegetable gardens until they have composted for at least 6–12 months, as fresh wood chips can temporarily tie up soil nitrogen as they decompose. Chipped wood from diseased trees should be disposed of rather than reused.