A baseboard length calculator figures out exactly how many linear feet of trim you need. Enter room dimensions and door count to get the total length to buy — including a waste factor for cuts.
Room Dimensions
Deductions
How to Calculate Baseboard Trim
Baseboard runs along the base of every wall except where there are doorways. To calculate the amount needed, add up all wall lengths and subtract 3 feet for each standard door opening. Add 10% for waste on miter cuts and end pieces.
Buying in Standard Lengths
Purchase boards in lengths that match your longest wall runs to minimize visible joints. A 14-foot wall should use a 16-foot piece (one cut) rather than a 12-foot and 2-foot piece (visible seam). Always round up to the next board length.
Estimates are approximate. Always measure your specific room before purchasing.
Frequently Asked Questions
How do I calculate baseboard length needed?
Measure the perimeter of the room (sum of all wall lengths). Subtract 3 feet for each standard doorway opening. Add 10% for waste and miter cuts. This calculator does all that for you.
How long are baseboard pieces at the store?
Baseboards are typically sold in 8-foot, 12-foot, or 16-foot lengths. Factor in the longest uninterrupted run in your room when choosing board length to minimize seams.
Do I need inside or outside corner pieces?
For inside corners, wood trim is coped or mitered at 45 degrees — no special piece needed. For outside corners (like kitchen islands or bay windows), you need a 45-degree miter cut. The waste factor in this calculator covers these extra cuts.
What is baseboard typically made from?
Finger-jointed pine (painted), solid pine, MDF (for painted applications), PVC (for wet areas), and hardwoods for stained finishes. MDF baseboard is the most common for new construction since it paints very smoothly.
Is this calculator free?
Yes, completely free with no signup required.