How to use this mulch calculator
- Enter your project dimensions and choose US or metric units.
- Check the product coverage or yield on its packaging. Optional prices are in USD.
- Select Calculate to see your estimate. If you change measurements, calculate again.
- Save the valid result to your project board, copy its link or print it.
The calculation explained
Area in square feet = bed length × bed width. Multiply by mulch depth in feet to get cubic feet. Divide by 27 for cubic yards. Add any allowance and round bag counts up.
Worked example
A 20 × 10 ft garden bed at 3 inches deep requires 200 × (3 ÷ 12) = 50 cubic feet before allowance. That is about 1.85 cubic yards. At 2 cubic feet per bag, 25 bags cover the theoretical volume.
What to check before you buy
A rectangular model is appropriate for simple beds. For irregular shapes, split the space into manageable sections. Check garden guidance for suitable mulch depth and avoid direct contact with trunks or siding.
These figures are estimates, not final purchase orders, professional installation instructions or engineering advice. The product packaging and site conditions take precedence over default values. When in doubt, confirm with a qualified contractor, supplier or relevant professional.
Frequently asked questions
How many cubic feet are in a cubic yard?
There are 27 cubic feet in one cubic yard.
How deep should I spread mulch?
Depth depends on the mulch type and landscape conditions; a few inches is common, but follow local horticultural recommendations.
Can I estimate bag price?
Yes. Enter your bag volume and price and the tool will round up the number of bags before calculating a shopping estimate.
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Metric worked example
A 6 × 3 m bed at 7.5 cm depth needs 1.35 m³ before allowance. With 10% extra, plan for 1.485 m³, or 30 bags of 0.05 m³ each.