Baseboard Calculator
Baseboard runs around the room, so you need the perimeter (2 × length + 2 × width) minus doorways, plus 10% waste. Enter your room size to get linear feet and boards.
How to measure baseboard
Baseboard follows the wall, so the quantity is the room perimeter: 2 × length + 2 × width. Subtract the width of each doorway, since trim stops at the openings. Add 10% for the waste from mitered corners.
Turning feet into boards
Trim is sold in fixed lengths — commonly 8, 12, or 16 feet. Divide the total linear feet (with waste) by your board length and round up. Longer boards mean fewer joints on long walls.
Cost
Multiply boards by the price each. For the floor that meets the trim, see the flooring calculator; for the room area itself, use the square footage calculator.
Frequently asked
How much baseboard do I need?
Add up the room perimeter — twice the length plus twice the width — subtract door openings, then add 10% for miter cuts. A 12×10 ft room with one doorway needs about 41 linear feet.
How many boards is that?
Divide the linear feet (including waste) by your board length and round up. At 8-foot boards, 41 feet of trim is 6 boards.
Why add 10%?
Mitered corners and scarf joints waste material, and a damaged end means recutting. Ten percent covers a typical room; add more for many corners.