Baseboard & Trim Calculator
Calculate linear feet of baseboard, crown molding, chair rail or quarter round - and how many sticks to buy.
The baseboard and trim calculator returns the linear feet you need and the number of sticks to buy. Enter the room length and width and the calculator works out the perimeter. For baseboard and quarter round it subtracts door openings (because trim stops at the casing). For crown molding and chair rail it uses the full perimeter, since these run continuously above doorways. 16 ft sticks are the most efficient because long walls take one piece instead of two with a seam; 8 ft sticks fit in a car but waste more material in long rooms. Plan on 10% waste for standard installs, 15% for stained trim where mismatched grain is visible, and 20% for complex profiles needing many miter cuts.
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Frequently asked questions
A 12 ft x 10 ft room has a 44 ft perimeter. Subtract one 32 inch door opening (2.67 ft) and you need 41.3 linear feet of baseboard. With 10% waste that is 46 feet, or 3 sticks of 16 ft trim (or 6 sticks of 8 ft). Crown molding for the same room runs the full 44 ft perimeter because it crosses above the door.
Baseboard stops where door casing starts - the casing covers the wall-to-floor joint at the doorway. Crown molding runs along the ceiling, which has no breaks at doorways, so it continues uninterrupted around the room. Quarter round and shoe molding follow the baseboard pattern. Chair rail can go either way depending on the design - it usually runs full perimeter for a continuous look.
16 ft sticks are the most efficient if you can transport them - one long piece per wall with no seams. 14 ft and 12 ft sticks are easier to handle solo and fit in most cars. 8 ft sticks are cheap and easy to carry but waste the most material in rooms with walls longer than 8 ft (every wall needs at least one joint, which means cutting and matching scarf joints).
A rectangular room has 4 inside corners and 0 outside corners. Rooms with bump-outs (closets that protrude, partial walls, columns) add outside corners. Inside corners are coped (one piece cut to match the profile of the other) for the best fit; outside corners are mitered at 45 degrees. The calculator assumes a rectangle - add 1 stick per outside corner to your buy list.
Yes for painted trim - caulk fills the gaps at scarf joints, miters and where trim meets the wall and floor. Use paintable acrylic caulk. Stained trim should not be caulked because caulk does not take stain - instead, cut tighter joints, use color-matched putty for nail holes, and accept that small gaps will show. This is why stained trim needs 15% waste vs 10% for painted.