Yard Materials
How to Calculate Mulch
Measure bed area, choose mulch depth, and convert cubic feet into bags or cubic yards.
Open Mulch CalculatorMeasure the bed area
For rectangular beds, multiply length by width. For curved beds, measure a practical rectangle around each section or split the bed into smaller shapes and add them.
Choose depth before shopping
Depth has a large effect on quantity. A 100 square foot bed at 2 inches needs 16.67 cubic feet. The same bed at 3 inches needs 25 cubic feet.
Convert to bags or bulk yards
Bagged mulch is usually labeled in cubic feet. Bulk mulch is commonly sold by cubic yard. Divide cubic feet by 27 to compare bulk pricing.
Use The Calculator With This Guide
This guide explains the measuring method, while the Mulch Calculator turns the same measurements into project quantities, waste-adjusted results, and a copyable shopping list. Use the guide first when you are deciding what to measure, then use the calculator when you are ready to compare material amounts.
Open Mulch CalculatorMeasurement Checks
- Entering mulch depth in feet instead of inches.
- Buying by bag count without checking the bag cubic-foot size.
- Refreshing old mulch with the same depth as a new bed.
Formula Reference
Area = length_ft × width_ft × number_of_areas
Cubic feet = area_sqft × depth_inches / 12
Cubic yards = cubic_feet / 27
Bags = adjusted_cubic_feet / bag_size
FAQ
Can I use the same depth for old and new beds?
Not always. Refreshed beds often need less mulch than new beds because old mulch may still be present.
Do tree rings need a different estimate?
Use the circular area around the tree and keep mulch away from the trunk. Do not pile mulch against bark.