Crown Molding Calculator

Calculate the total length of crown molding required for your room.

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How to Calculate Crown Molding

To determine the total length of crown molding required for a room, use the formula:

Perimeter = 2 × (Length + Width)
Total Molding = Perimeter × (1 + Wastage Allowance)

  • Length and Width: Room dimensions in feet or meters.
  • Wastage Allowance: A percentage to account for cutting and mistakes, typically around 10%.

Our calculator simplifies this by automatically applying the formula based on your input values.

Example:

You’re installing crown molding in a room that’s 12 feet long and 10 feet wide. You allow for 10% wastage.

  1. Calculate the perimeter:
    2 \times (12 + 10) = 44 \, \text{ft}
  2. Add the wastage allowance:
    44 \times (1 + 0.10) = 48.4 \, \text{ft}

You need approximately 48.4 feet of crown molding.