Mulch Calculator
Enter your bed dimensions and desired depth to get bags or cubic yards of mulch to buy.
Enter your measurements to see what to buy.
How to calculate it
Enter your bed dimensions and desired depth to get bags or cubic yards of mulch to buy.
Source: Volume = area × depth; 1 cubic yard = 27 cubic feet. Bagged mulch is commonly sold in 2 or 3 cu ft bags.
A 10×4 ft bed at 3 in deep = 10 ft³. In 2 cu ft bags: 5 bags before waste, 6 bags with 5% waste. In bulk: 0.37 yd³.
Want the full step-by-step walkthrough? Read our How Much Mulch Do I Need? A Bed-by-Bed Guide.
Mulch coverage by depth
How far mulch goes depends almost entirely on depth. This table shows the square footage one cubic yard covers at common spreading depths, plus how many bags equal a yard.
| Mulch depth | Coverage per cubic yard | 2 cu ft bags per yard | 3 cu ft bags per yard |
|---|---|---|---|
| 1 in (refresh) | 324 ft² | 13.5 bags | 9 bags |
| 2 in | 162 ft² | 13.5 bags | 9 bags |
| 3 in (standard) | 108 ft² | 13.5 bags | 9 bags |
| 4 in (paths/playgrounds) | 81 ft² | 13.5 bags | 9 bags |
One cubic yard = 27 cubic feet. Bulk by the yard is usually cheaper once you need more than about 13 bags of 2 cu ft mulch.
How to use this calculator
- Enter your bed length and width in feet and inches, then the desired mulch depth in inches.
- Toggle between bag and bulk mode to see bag counts or cubic yards.
- 2–3 in is standard for garden beds; 1 in refreshes existing mulch.
- Add your price per bag or per cubic yard for an optional cost estimate.
Purchasing & waste guidance
- 2–3 in is ideal for most garden beds — enough to block weeds without suffocating roots.
- 1 in is enough to refresh existing mulch; 4 in+ for paths and playgrounds.
- One cubic yard covers about 108 ft² at 3 in deep, or 162 ft² at 2 in.
- Bulk by the cubic yard is usually cheaper once you need more than about 13 bags (2 cu ft each).
Waste factor guidance
- 5% covers settling and uneven spreading on a typical bed.
- Use 10% for irregular beds with curves where spreading is less even.
- Skip the waste allowance only for precise, edged rectangular beds.
Common mistakes to avoid
- Piling mulch against tree trunks or house siding — keep it a few inches back to prevent rot.
- Ordering by the bag when you need more than about 13 bags — bulk by the yard is cheaper.
- Spreading too deep (over 4 in) in planting beds, which can suffocate roots.
Assumptions & what’s included
- Bed is a single rectangle; depth is the finished mulch depth.
- Waste allowance covers settling and uneven spreading.
- Price is per bag (bag mode) or per cubic yard (bulk mode) and optional.
Sources & references
- Bag sizes (1, 2 and 3 cu ft) and bulk cubic-yard coverage follow common landscape-supplier convention; 1 cubic yard = 27 cubic feet.
- Depth guidance (2–3 in beds, 1 in refresh, 4 in+ paths) follows common horticultural and extension-service recommendations.
- Coverage per cubic yard is computed from volume = area × depth; confirm bag size on the product label.
Learn more about how every calculator works on our methodology page.
Frequently asked questions
How many bags of mulch equal a cubic yard?
One cubic yard equals 27 cubic feet, so it takes 13.5 bags of 2 cu ft mulch or 9 bags of 3 cu ft mulch to make a cubic yard.
How deep should mulch be?
2–3 in is standard for garden beds. Use 1 in to refresh existing mulch, and 4 in or more for paths and playgrounds. Avoid piling mulch against tree trunks.
How much mulch do I need for a 10×10 bed?
A 10×10 ft bed at 3 in deep needs about 25 ft³, or 0.93 yd³ with a 5% waste allowance — roughly 13 bags of 2 cu ft mulch.
How many cubic yards is a scoop of mulch?
A typical scoop from a landscape supplier is about 1 cubic yard, though scoop size varies. One cubic yard covers roughly 108 ft² at 3 in deep — use that to compare bulk pricing to bags.
How much mulch do I need for a 100 sq ft bed?
A 100 ft² bed at the standard 3 in depth needs about 25 ft³, or 0.93 cubic yards with a 5% settling allowance. That is roughly 13 bags of 2 cu ft mulch.
Should I remove old mulch before adding new?
No — refreshing is better than replacing. Add about 1 in of new mulch on top of thinned existing mulch to restore color and coverage. Total mulch depth should stay around 3 in for beds; avoid piling it deeper than 4 in.
Related guides
Step-by-step project guides that use this calculator.