Landscaping
Mulch Calculator
Estimate mulch volume in cubic feet and cubic yards, with optional settling overage and bag count.
Calculator inputs
Mulch Calculator Results
Results update in your browser as you edit inputs. They are planning estimates, not complete shopping lists.
Enter project dimensions to calculate material quantity.
Assumptions
- The bed is treated as a rectangle with even depth.
- Existing mulch, slopes, plant displacement, and settling are simplified into the optional overage factor.
- Bag count is shown only when a bag size is entered.
- For bulk mulch, use cubic yards. For bagged mulch, use the bag count based on the bag size printed on the package.
- Cost outputs use only the unit prices you enter.
Formula
- Cubic feet = length x width x depth in feet.
- Cubic yards = cubic feet divided by 27.
- Overage volume = base volume x (1 + settling / overage factor).
- Bags = overage cubic feet divided by bag size, if a bag size is entered.
How to Use the Mulch Calculator
- Enter the bed length and width in feet.
- Enter the mulch depth in inches.
- Add a settling or overage factor for uneven beds and field loss.
- Enter bag size if you are buying bagged mulch.
- Use cubic yards for bulk mulch and bag count for packaged mulch.
Mulch Calculator Examples
500 sq ft bed at 2 in deep
A 500 sq ft bed at 2 in deep needs about 83.33 cu ft before overage. With 10% overage, it is about 91.67 cu ft, or about 3.40 cu yd.
- Area: 500 sq ft
- Depth: 2 in
- With 10% overage: about 91.67 cu ft
- Bulk volume: about 3.40 cu yd
100 sq ft bed at 3 in deep
A 100 sq ft bed at 3 in deep needs about 25 cu ft before overage. With 10% overage, it is about 27.5 cu ft, or 14 bags if each bag contains 2 cu ft.
- Area: 100 sq ft
- Depth: 3 in
- With 10% overage: about 27.5 cu ft
- Bag count: about 14 bags at 2 cu ft each
Units and Parameters Quick Reference
Mulch volume inputs
Mulch is usually planned by cubic yards for bulk orders or by bag count for packaged mulch.
| Input | Unit | Planning note |
|---|---|---|
| Area length and width | ft | Used to calculate bed area. |
| Depth | in | Converted to feet for volume. |
| Settling overage | % | Adds extra for settling and irregular beds. |
| Bag size | cu ft | Used only for bag count. |
| Cubic yards | cu yd | Common bulk mulch planning unit. |
Plant spacing, existing mulch, slopes, borders, and delivery minimums are not included.
Example calculation
Example: 500 sq ft bed
A 25 ft by 20 ft bed is 500 sq ft. At 2 in deep, it needs about 83.33 cubic feet, or 3.09 cubic yards, before overage.
Common mistakes
- Entering depth in feet instead of inches.
- Forgetting mulch settles after installation.
- Using bag count without checking the bag size.
FAQ
What mulch depth should I use?
Many garden beds use roughly 2 to 3 inches, but plant needs and existing mulch depth matter.
Does this calculate bulk delivery price?
No. It estimates quantity only. You can enter your own bag price for a simple cost estimate.
How much mulch do I need for 100 square feet?
At 2 inches deep, 100 sq ft needs about 16.67 cu ft before overage. At 3 inches deep, it needs about 25 cu ft before overage.
Should I buy mulch by bags or cubic yards?
Use bag count for small projects and cubic yards for bulk planning. The calculator can show both when you enter bag size.
Should I add extra mulch for settling?
Often yes. A 5% to 10% overage can help with settling, uneven beds, and small spreading losses.
Related Planning Tools
Use these related calculators when the same project needs another material estimate. Each link opens a browser-based tool with its own assumptions and formulas.
Related Material Guides
Read these planning guides when you want more context for the assumptions, depth, thickness, waste factor, or bag-yield inputs used by this calculator.