Baseboard Calculator: How Much Baseboard Do I Need?
Enter each room and how many doorways it has. Trim is sold in fixed stock lengths, so the useful answer is a piece count rather than a footage — and the piece count depends on which length you buy.
Rooms and doorways
Enter a room by its dimensions, or switch to a run you have measured directly.
Trim is sold by the stick, so the cost figure charges for whole pieces including the offcuts. Buy a little more than the number says if the profile is one you would struggle to match later.
How much baseboard do I need?
Trim runs around the room, so start with the perimeter rather than the area. Subtract the doorways, add an allowance for mitre cuts, then divide by the length of stick you are buying.
Longer sticks usually mean fewer pieces and fewer joints, but a 16 ft length is awkward to transport and to carry up a staircase. It is worth checking that what you buy fits in the car before you order it.
Stock lengths
| Stock length | Trade-off |
|---|---|
| 8 ft | Easy to handle, more joints on a long wall |
| 12 ft | A good default for most rooms |
| 16 ft | Fewest joints, hardest to transport |
A joint in the middle of a long wall is visible, so where you can, buy a length that spans the wall in one piece. Where you cannot, a scarf joint over a stud disappears far better than a butt joint.
How much waste to allow
| Waste | Good starting point for |
|---|---|
| 5% | Square rooms with few corners |
| 10% | A typical room with several corners |
| 15% | Many corners, angles, or a pattern to match |
Trim waste comes from mitres. Every internal and external corner costs an angled cut and the offcut is usually too short to use, so a room with a chimney breast and an alcove wastes far more than a plain rectangle.
How to measure
Length and width are enough — the perimeter is worked out for you.
If a room is not a rectangle, measure each wall and enter the total as a length.
Trim stops at a doorway. A cased opening with no door still counts.
Common mistakes
- Buying the exact footage and having nothing left for a mis-cut mitre.
- Forgetting that a doorway removes its own width from the run.
- Buying 16 ft sticks that will not fit up the stairs.
- Ordering trim before the flooring, then finding it sits at the wrong height.
Laying the floor first?
Baseboard goes on after the flooring — work that out before you cut trim.
Open the Flooring Calculator →