Baseboard Calculator
Calculate the linear feet of baseboard you need for a room, minus doorways, with waste factored in and pieces rounded to stock length.
Pieces to buy
7pieces
With waste
53.9ft
Net linear feet
49ft
Room perimeter
52ft
Assumes a standard 3 ft doorway width per opening. Measure wider openings (sliders, archways) and adjust manually for a tighter estimate.
How the baseboard calculator works
Baseboard runs along the room's perimeter, minus any doorway openings, then gets a waste allowance for miter cuts before being converted into how many stock-length pieces to buy.
Formula: perimeter = 2 × (length + width). Net linear feet = perimeter − (doorways × 3 ft). With waste = net × (1 + waste% ÷ 100). Pieces = with waste ÷ stock length, rounded up.
Frequently asked questions
Measure the room's perimeter (the distance around the floor where the wall meets it), then subtract the width of each doorway — baseboard doesn't run across an open doorway the way it does along a solid wall.
10% is the standard allowance for a typical rectangular room to cover miter cuts and mistakes. Rooms with lots of corners, bay windows, or angled walls warrant closer to 15%, and premium or patterned moldings can justify 15-20%.
Standard stock lengths are 8, 10, 12, and 16 feet. Set the stock length field to match what's available at your supplier to see exactly how many pieces to buy.
Yes, if they'll be trimmed with baseboard — include their perimeter in your measurement. For irregularly shaped rooms, break the space into simple rectangles and add the perimeters together.