Mulch Calculator
Calculate how much mulch you need for your garden or landscaping based on area and desired depth.
How to use the Mulch Calculator
- Enter your inputs into the Mulch Calculator above.
- Results update instantly as you type — no submit button needed.
- Adjust any value to see how the result changes in real time.
The mulch volume formula
Cubic yards = (Area ft² × Depth inches) / 324
324 converts square feet × inches to cubic yards (1 yd³ = 27 ft³ = 27 × 12 in × ft² = 324). For metric: cubic meters = area m² × depth m.
Worked example
300 sq ft of garden bed mulched 3 inches deep: cubic yards = (300 × 3) / 324 ≈ 2.78 yd³. Round up to 3 yards. Bagged mulch is typically 2 cu ft per bag, so ~37 bags would be equivalent.
Frequently asked questions
How deep should mulch be?
2–3 inches for established beds, 3–4 inches for new beds. Deeper than 4 inches can suffocate plants and harbor pests. Refresh annually as mulch decomposes.
Bagged vs. bulk mulch?
Bulk (yardage) costs less per cu ft for large projects, but requires a trailer or delivery. Bagged is cheaper for small projects and easier to handle.
What's the best mulch type?
Depends on use. Shredded hardwood: longest-lasting, common for ornamental beds. Pine bark: acidic, good for shrubs/conifers. Rubber mulch: long-lasting but doesn't enrich soil. Straw: good for vegetable gardens.