Trim & Baseboard Calculator
Linear feet of baseboard, crown, or chair rail for a room — and the number of stock lengths to buy, with corner waste and cost included.
Trim is sold in fixed stock lengths, so the real question isn't the linear feet — it's how many 8, 12, or 16-foot pieces to buy once corners and offcuts are accounted for. This calculator does that for baseboard, crown, and chair rail, each with the right perimeter logic, and adds the material cost.
Pair it with the Paint Calculator for the walls above and the Renovation Budget Estimator for the full room.
FAQ
- How much baseboard do I need?
- Start with the room perimeter (2 × [length + width]), subtract the width of door openings, then add a cut-waste allowance for mitered corners. The calculator converts that run into the number of stock lengths to buy and rounds up.
- Does crown molding subtract doors like baseboard?
- No. Crown and chair rail run continuously around the room above or across door openings, so the full perimeter applies. Only baseboard skips the door gaps, which is why the calculator treats them differently.
- How much waste should I allow?
- 10% is a good default for cut-offs and mitered corners. Bump it to 15% for a room with many corners, or if you're matching a profile across joints where short offcuts can't be reused.
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