Baseboard Calculator — Linear Metres and Pieces Needed
Baseboard runs the perimeter of a room minus door openings. Getting the right linear metre count before heading to the timber yard saves a return trip — and ensures you buy from the same lot for consistent colour and grain.
How we calculate
Perimeter = 2 × (length + width). Deduct ~0.9 m per door opening. Pieces = ⌈(linear metres ÷ piece length) × (1 + waste %)⌉.
Worked example
4 m × 3 m room, 1 door, 2.4 m pieces, 10% waste. Perimeter = 14 m, deduct 0.9 m → 13.1 m. Pieces = ⌈(13.1 ÷ 2.4) × 1.1⌉ = 7 pieces.
Common mistakes
- Not deducting door openings — you don't run skirting across door frames.
- Forgetting that inside and outside corners require mitre cuts that add waste.
- Buying random lengths from different batches — colour variations are hard to hide.
Frequently asked questions
How do I measure linear metres of baseboard needed?+
Measure the perimeter of the room (add all wall lengths together) and subtract about 0.9 m for each door opening. That gives you the net linear metres. Add 10% for waste from mitre cuts at corners.
What length pieces of baseboard should I buy?+
Standard lengths are 2.4 m, 3.6 m, and 4.2 m. Choose a length close to your longest wall to minimise joins. Fewer joins means a cleaner finish and less filler work.
Why do I need a waste allowance for baseboard?+
Every inside and outside corner requires a mitre cut, which wastes the end of each piece. A 10% allowance covers typical four-corner rooms. Rooms with bay windows or alcoves need 15% or more.
Should I buy all my baseboard from the same batch?+
Yes. Wood and MDF profiles can vary slightly in colour and grain between batches or production runs. Buying all pieces at once from the same batch ensures a consistent look across the room.