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 the actual bag volume printed on a product. The additional bag-size comparisons are illustrative only.
- 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.
- Enter the cubic-foot volume printed on the mulch bag for an estimated whole-bag count, or leave it blank for bulk volume only.
Formula and methodology
Area = length × width. Volume in cubic feet = area × depth in feet. Cubic yards = cubic feet ÷ 27. Estimated purchase volume = calculated volume × (1 + extra percentage ÷ 100). When bag volume is entered, estimated bags = purchase volume ÷ bag volume, rounded up.
Important: This is a planning estimate. Bed shape, grade, compaction, settling, and actual spread depth can change the amount used.
How accurate is this estimate?
Area and volume come directly from the entered dimensions and the fixed cubic-foot-to-cubic-yard conversion. The purchase estimate adds your selected extra-material percentage. A primary bag count appears only when you enter product-specific bag volume; confirm that volume and the bulk ordering increment before purchasing.
Worked example
A 20 ft × 12 ft bed at 3 in deep covers 240 sq ft and calculates to 60 cu ft, or about 2.22 cu yd. With 10% extra, the purchase estimate is about 2.44 cu yd (66 cu ft). A product containing 2 cu ft per bag would require an estimated 33 whole bags.
Before you buy
- Subtract large areas that will not receive mulch by calculating them separately.
- Use the bag volume printed on the product for a purchasing estimate; the other displayed bag sizes are examples only.
- 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 calculated or purchase-estimate amount?
Bag counts use the estimated purchase 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 estimated quantities. Additional shapes can be added later.