Crown Molding Calculator

About this calculator

This calculator sums a room's wall perimeter to find the total linear length of crown molding needed, then adds a waste allowance — typically 10-15% — to cover the 45-degree miter cuts at each corner, which consume extra material and inevitably produce offcuts too short to reuse, before dividing the total by the standard stick length (8 feet, or 2.4 m) to give a shopping-list piece count.

Finish carpenters and general contractors use this waste-inclusive method when quoting jobs and ordering material, since underordering molding mid-project often means a second trip to the supplier with mismatched dye-lot batches, while DIY homeowners use it to buy the right number of sticks the first time.