Garden calculator
Mulch Calculator
Estimate mulch in cubic yards, complete bags, and bulk increments, with a side-by-side purchase cost.
Planning estimate, not a contractor quote. Review the assumptions and replace presets with local prices when available.
Method
How this calculator works
Bag labels commonly describe volume, so compare bagged and delivered bulk material on the same cubic-foot basis. Keep already-present mulch separate from the additional layer you plan to add. Enter bag volume from the package and bulk increments from the supplier. The calculator applies one visible purchase allowance and reports both supply methods as alternatives.
Layer ft³ = length × width × depth in inches ÷ 12. Adjusted ft³ = layer ft³ × (1 + allowance ÷ 100). Bags = round up(adjusted ft³ ÷ bag ft³). Bulk order = adjusted yd³ rounded to the selected increment.
Worked example
A realistic starting point
At 20 × 10 ft and 3 inches, the measured layer is 50.00 ft³. With a 10% allowance it becomes 55.00 ft³, requiring 28 complete 2 ft³ bags. Bulk delivery is rounded separately to your selected increment.
What changes the answer
Factors worth checking
New material depth
Measure the layer being added. Including both existing material and the full desired finished depth overstates the new purchase.
Bag volume and delivery
A bag’s weight is not a substitute for its volume. Compare the stated cubic feet with bulk cubic yards, and add delivery only to the option that incurs it.
Allowance versus application
The purchase allowance helps cover quantity uncertainty. It does not instruct you to apply a thicker layer everywhere. Keep any excess for an appropriate later use.
Common questions
Mulch FAQ
How many 2 ft³ bags are in one cubic yard?
One cubic yard contains 27 ft³, equivalent to 13.5 bags of 2 ft³. Buying 14 complete bags provides 28 ft³; this is purchase rounding, not an extra application-depth recommendation.
Why are bagged and bulk quantities different?
Each method rounds to different package increments. The underlying adjusted volume is the same, but purchased volume can exceed it by different amounts.
Can I price several bag sizes?
Change bag volume and price in the comparison scenario. Compare final costs and purchased volumes, not just the sticker price of one bag.
Evidence
Sources & review
- University of Minnesota Extension — mulchingOrganic and inorganic mulch behavior; application depth depends on the landscape.
- NIST — SI units: volumeUnit relationships; supplier product coverage and prices remain separate inputs.
Published by Calcstead. Report a correction.
Method and source links reviewed September 6, 2026. Price presets are editable planning inputs and should be replaced with current local information.