Baseboard & Crown Molding Calculator
Enter your room dimensions to calculate exactly how much baseboard or crown molding you need, in linear meters and standard pieces.
Room dimensions (meters)
Works for both baseboard and crown molding — the math is the same room perimeter either way. Door/opening deductions use standard 0.9m door and 1.0m open-doorway widths.
Frequently asked questions
How do I calculate how much baseboard I need?
Measure the room's perimeter (2 × (length + width)), then subtract the width of any doorways. Add a 10% waste buffer for cuts and mistakes at corners. A 4m × 3m room has a 14m perimeter — minus one 0.9m door, that's about 14.3m of baseboard after waste.
Do baseboard and crown molding use the same calculation?
Yes — both run around the room's perimeter, so the math is identical. The main difference is that crown molding usually doesn't get interrupted by doorways the way baseboard does, so you may need fewer deductions.
How long are standard trim pieces?
Baseboard and crown molding typically come in 8 ft (2.4 m), 10 ft (3 m), or 12-16 ft (4-4.9 m) lengths. Longer pieces mean fewer seams but can be harder to transport and maneuver into a room.
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