πΏ Mulch Calculator
Calculate cubic yards and bags of mulch needed for your garden beds.
Mulch Needed
How to Use This Calculator
Enter the length and width of each garden bed or landscaping area, set the desired mulch depth in inches, and choose your bag size. Add multiple areas using the "Add Another Area" button. The calculator gives you total cubic yards for bulk ordering or the number of bags to buy at the store.
Measure each garden bed or landscaping area in feet. For curved or irregular beds, estimate the overall length and average width.
Set the depth. Use 2 inches for refreshing existing beds. Use 3 inches for new beds or where weed suppression is a priority. Avoid going over 4 inches against plant stems.
Add all your areas using the "Add Another Area" button for a combined total.
Check the cubic yards total. If you need more than 3 cubic yards, buying bulk mulch by the yard from a landscape supply company is almost always cheaper than bagged mulch from a big-box store.
Mulch Volume Formula
A 3 cubic foot bag of mulch covers 12 square feet at 3 inches deep, or 18 square feet at 2 inches deep. A cubic yard covers 108 square feet at 3 inches deep. For a typical 400 square foot front yard bed at 3 inches, you need about 3.7 cubic yards or 33 bags of 3 cubic foot mulch.
Example Projects
Tips for Your Project
Pull weeds before you mulch, not after. A fresh layer of mulch does not kill existing weeds. It just hides them temporarily while they grow under cover. For serious weed problems in new beds, lay a layer of cardboard or 4 to 6 sheets of newspaper directly on the soil before adding mulch. The cardboard smothers weeds and breaks down over one season without harming soil health.
Keep mulch 2 to 3 inches away from plant stems and tree trunks. Mulch piled against stems holds moisture against the bark and creates an environment for rot and disease. The common "mulch volcano" look around trees actually kills trees slowly over several years. Spread the mulch out in a flat layer, not a mound, and keep it away from the base of every plant.
Frequently Asked Questions
How deep should mulch be?
2β3 inches for established beds. 3β4 inches for new plantings or weed suppression. Avoid piling mulch against plant stems (mulch volcanoes) which cause rot.
How much does a bag of mulch cover?
A standard 2 cubic foot bag covers 12 sq ft at 2" depth or 8 sq ft at 3" depth. A 3 cubic foot bag covers 18 sq ft at 2" depth.
How many cubic feet in a cubic yard?
27 cubic feet = 1 cubic yard. Bulk mulch is typically sold by the cubic yard; bagged mulch is sold in 2 or 3 cubic foot bags.
When should I apply mulch?
Spring (after soil warms) and fall (before ground freezes). Avoid applying mulch when soil is wet, which can promote fungal disease.
What type of mulch lasts longest?
Hardwood bark mulch: 3β5 years. Cedar/cypress: 3β5 years. Pine bark: 2β3 years. Wood chips: 1β2 years. Rubber mulch: 10+ years.