Baseboard runs around the walls and stops at the doorways, so you need the room’s perimeter minus the doors. A 4.5 × 3.5 m room with one 0.9 m doorway needs 2 × (4.5 + 3.5) − 0.9 = 15.1 m of baseboard; with 10% extra for corner cuts, 7 pieces of 2.4 m. Enter the room (or the total length of irregular walls), the doorways and the piece length, and the calculator gives the linear length, the pieces, the corners and the cost.
Typical rooms, one door, 10% extra
| Room | Perimeter | Baseboard (minus 0.9 m or 3 ft door) | Pieces |
|---|---|---|---|
| 3 × 3 m | 12 m | 11.1 m | 6 × 2.4 m |
| 4.5 × 3.5 m | 16 m | 15.1 m | 7 × 2.4 m |
| 5 × 4 m | 18 m | 17.1 m | 8 × 2.4 m |
| 10 × 10 ft | 40 ft | 37 ft | 6 × 8 ft, or 4 × 12 ft |
| 12 × 12 ft | 48 ft | 45 ft | 7 × 8 ft, or 5 × 12 ft |
| 14 × 16 ft | 60 ft | 57 ft | 8 × 8 ft, or 6 × 12 ft |
Corners and joints
In a room with square corners, the inside corners are always four more than the outside ones, so the calculator only asks how many outside corners there are (a chimney breast adds two of each). Inside corners are usually coped or mitered; outside corners are mitered at 45°. Each joint along a wall uses a scarf cut, which eats a little length: that is what the 10% covers.
Buying tips
- Buy pieces at least as long as the longest wall when you can.
- Count one doorway per opening, and add the width of any built-in cabinets that the baseboard will not run behind.
- Paint or stain before installing, then touch up the nail holes.
- If you are also laying a floor, the flooring calculator gives the same perimeter.
Once zet4u is saved, this calculator works offline, handy at the lumberyard.
Frequently asked questions
How do I measure for baseboard?
Add up the length of every wall (for a rectangular room, 2 × length + 2 × width) and take off the width of each doorway. A 4.5 × 3.5 m room with one 0.9 m door needs 16 − 0.9 = 15.1 m.
How many pieces of baseboard do I need?
Add about 10% for the corner cuts and divide by the length of one piece, rounding up. 15.1 m + 10% = 16.6 m, which is 7 pieces of 2.4 m.
How many linear feet of baseboard for a 12 × 12 ft room?
48 ft of wall, minus a 3 ft door: 45 linear ft. With 10% extra, 49.5 ft: four 16 ft pieces, five 12 ft pieces or seven 8 ft pieces.
How many corners does a room have?
A room with square corners always has four more inside corners than outside ones: a rectangle has 4 and 0, an L-shaped room 5 and 1, a room with a chimney breast 6 and 2.
What length of baseboard should I buy?
The longest you can carry and fit: a wall without a joint looks better. Common lengths are 2.4, 3 and 4.2 m, or 8, 12 and 16 ft.
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