Baseboard Trim Calculator

Accounting for doorways in a trim order

Baseboard runs continuously around a room's perimeter except where doorways interrupt it, so an accurate material estimate has to subtract those door opening widths from the raw perimeter measurement.

Worked example

For a room with a 48ft perimeter and 6ft of combined door opening widths:

Trim Length = 48 - 6 = 42 ft

Frequently asked questions

Should I buy exactly 42 feet of trim? No - add roughly 10% extra beyond the calculated figure to cover angled corner cuts (most baseboard corners are mitered at 45 degrees, which wastes some material) and any measuring mistakes during installation.

Do closets and alcoves count in the perimeter? Yes - measure around every wall segment that will actually receive baseboard, including closet interiors and alcoves, not just the main rectangular footprint of the room.