Baseboard and Trim Calculator
Example: Room perimeter: 60 ft · Number of doorways: 2 openings · Width per doorway: 3 ft · Waste allowance: 10 % · Price per linear foot: 2 $ · Stock piece length: 12 ft
| Linear feet needed | 59.4 |
| Stock pieces to buy | 5 |
| Total trim cost | $119 |
Worked example
A room with a 60-foot perimeter and two 3-foot doorways has 60 minus 6 = 54 feet to trim. Adding 10% for miter waste gives about 59.4 linear feet. In 12-foot stock pieces that is 5 pieces, and at $2 a foot the trim costs about $119. Buying whole 12-foot lengths means the count of pieces, not just the footage, drives your trip to the lumberyard.
Frequently asked questions
Do I subtract doorways from baseboard?
Yes for baseboard, since the floor line is broken at each door opening. Casing that wraps around the door is a separate calculation. This tool subtracts the doorway widths from the perimeter so your baseboard footage reflects the runs that actually get trim.
How much waste for trim?
Around 10% covers mitered outside corners, coped inside corners, and the occasional bad cut. Long walls that exceed your stock length also force joins that waste a little, and intricate rooms with many corners waste more, so lean toward the higher end for complex layouts.
Why does the piece count matter, not just the footage?
Trim comes in set lengths like 8, 12, or 16 feet, and you cannot buy a partial stick. A wall longer than one stock piece needs a scarf joint, and short leftover offcuts often cannot be reused, so the number of whole pieces is what you actually purchase and carry home.
Should I buy longer sticks to reduce joints?
Longer stock means fewer visible joins on long walls, which looks cleaner, but the pieces are harder to transport and handle and can waste more if your walls are short. Match the stock length to your longest walls where possible to minimize seams.