Mulch Calculator
Estimate mulch volume in cubic feet and cubic yards, then compare whole-bag quantities with an adjustable extra-material allowance.
Instant estimate · No sign-up · Your measurements stay in your browser
Project details
Enter your measurements
Enter your project measurements. Planning defaults are identified where used. After your first calculation, edits update the estimate automatically.
Project estimate
Results
Enter your measurements, then select Calculate.
How to use this calculator
Measure the rectangular bed, choose the intended mulch depth, and compare bulk cubic yards with common bag sizes. The result keeps the measured need separate from the amount you may want to buy.
- Measure the longest length and width of the rectangular bed.
- Enter the finished mulch depth—typically measured after the material is spread.
- Adjust the extra-material percentage for irregular edges, settling, or measuring variation.
- Compare bulk volume with the whole-bag equivalents in the results.
Formula and methodology
Area = length × width. Volume in cubic feet = area × depth in feet. Cubic yards = cubic feet ÷ 27. Recommended volume = calculated volume × (1 + extra percentage ÷ 100).
Important: This is a planning estimate. Bed shape, grade, compaction, settling, and actual spread depth can change the amount used.
Worked example
A 20 ft × 12 ft bed at 3 in deep covers 240 sq ft and needs 60 cu ft, or about 2.22 cu yd. With 10% extra, the purchase estimate is about 2.44 cu yd (66 cu ft).
Before you buy
- Subtract large areas that will not receive mulch by calculating them separately.
- Bag coverage labels may use a stated depth; compare volume, not just a marketing coverage number.
- Bulk suppliers may sell in half-yard increments, so ask how they round orders.
Frequently asked questions
How many cubic feet are in a cubic yard of mulch?
One cubic yard contains 27 cubic feet. The calculator uses that fixed volume conversion.
Are bag counts based on the exact or recommended amount?
Bag counts use the recommended volume after the selected extra-material percentage and round up to whole bags.
Can I calculate an irregular bed?
For now, split the bed into several rough rectangles, calculate each, and add the recommended quantities. Additional shapes can be added later.