Mulch Calculator Formula

Understand the math behind the mulch calculator. Each variable explained with a worked example.

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Formulas Used

Cubic Yards Needed

cubic_yards = volume_cuft / 27

Bags (2 cu ft)

bags_2cuft = ceil(volume_cuft / 2)

Total Area

area_sqft_out = area_sqft

Variables

VariableDescriptionDefault
lengthArea Length(ft)20
widthArea Width(ft)10
depthMulch Depth(in)3
area_sqftDerived value= length * widthcalculated
depth_ftDerived value= depth / 12calculated
volume_cuftDerived value= area_sqft * depth_ftcalculated

How It Works

Mulch Calculation

Volume (cu ft) = Length × Width × Depth (in ft)

Cubic Yards = Volume / 27

Recommended mulch depth: 2-3 inches for most landscaping, 3-4 inches around trees.

Worked Example

20×10 ft area with 3 inches of mulch.

length = 20width = 10depth = 3
  1. 01Area = 20 × 10 = 200 sq ft
  2. 02Volume = 200 × (3/12) = 50 cu ft
  3. 03Cubic yards = 50 / 27 = 1.9 yards
  4. 04Bags (2 cu ft) = 50 / 2 = 25 bags

Ready to run the numbers?

Open Mulch Calculator