Landscaping & Outdoor
Mulch Calculator
Turn bed dimensions and mulch depth into a bulk volume and a practical whole-bag shopping estimate.
- Bulk & bagged estimates
- Editable bag size
- Waste allowance included
Enter your mulch bed
Measure the bed at its widest rectangular dimensions, then choose the finished mulch depth and the size printed on one bag.
Estimate result
How this estimate is calculated
The calculator multiplies bed length, width, and finished depth, then adds your selected allowance. It converts the adjusted volume to cubic yards for imperial projects or cubic metres and litres for metric projects.
Mulch volume = bed length × bed width × mulch depth × (1 + waste %)
Bag count divides the adjusted volume by the package size you enter and always rounds up. Irregular beds can be split into smaller rectangles and added together.
Mulch Calculator FAQs
How deep should mulch be?
A layer around 2 to 3 inches is common for many landscape beds. Avoid piling mulch against trunks or stems, and follow the plant and mulch supplier’s guidance.
How many 1.5 cubic foot bags are in one cubic yard?
One cubic yard contains 27 cubic feet, so it takes 18 bags at 1.5 cubic feet each before adding any allowance.
Why does the calculator add waste?
Mulch settles and beds rarely have perfectly straight edges. The adjustable allowance helps cover those small differences.
Can I use litres and cubic metres?
Yes. Metric mode accepts metres and centimetres, reports cubic metres and litres, and uses an editable litre bag size.
Suggested supplies
These non-affiliate Amazon search links can help you compare common project materials. Affiliate tracking can be enabled later from the shared site configuration.
Related project calculators
Continue planning with another calculator from the same BuildingMath site.