Baseboard Calculator

Find out how much baseboard, quarter round or shoe molding you need. Enter the room size and number of doorways to get the linear feet and the number of pieces to buy.

Baseboard needed49.5 linear ft

Pieces of 16 ft: 4 pieces
Room perimeter: 48 ft
Without extra: 45 linear ft

How this calculator works

Baseboard runs around the perimeter of the room: 2 × (length + width).

Doorways do not get baseboard, so about 3 feet is subtracted for each one.

An extra percentage covers miter cuts at the corners and short offcuts. The total is divided by the length of each piece and rounded up.

Example: a 12 × 12 ft bedroom with one door

Perimeter: 2 × (12 + 12) = 48 ft.
Subtract the doorway: 48 − 3 = 45 ft.
Add 10% for cuts: 49.5 ft.
With 16 ft pieces: 49.5 ÷ 16 = 3.1, so buy 4 pieces.

Quick reference

Baseboard for common rooms (1 doorway, 10% extra)
Room size	Linear feet	16 ft pieces
10 × 10 ft	40.7	3
12 × 12 ft	49.5	4
12 × 16 ft	58.3	4
15 × 20 ft	73.7	5

Baseboard for common rooms (1 doorway, 10% extra)

Room size

Linear feet

16 ft pieces

10 × 10 ft

40.7

12 × 12 ft

49.5

12 × 16 ft

58.3

15 × 20 ft

73.7

Tips before you buy

Longer pieces mean fewer joints along a wall. Buy pieces at least as long as your longest wall when you can.
Rooms with many outside corners, columns or bay windows need 15% extra or more.
Let wood trim acclimate in the room for a couple of days before cutting.

Frequently asked questions

How much baseboard do I need for a 12 × 12 room?

A 12 × 12 ft room has a 48 ft perimeter. Subtracting one doorway and adding 10% gives about 49.5 linear feet, or four 16 ft pieces.

Should I subtract doors when measuring baseboard?

Yes. Baseboard stops at the door casing, so subtract the width of each doorway — about 3 feet for a standard door.