Buying baseboard without overpaying or running short
How to turn a room measurement into a confident trim order, why waste and piece length drive the count, and where cut planning saves money.
From perimeter to a real shopping list
Linear feet is the honest unit for buying trim, because it ignores how the wall bends and only counts how far the baseboard has to travel. The tool starts from the room perimeter, twice the length plus twice the width, then removes the doorways your trim will not cross. What remains is the net run your walls actually need. Converting that run into whole boards is the step that decides how much you carry home, and it is where a small planning error becomes a second trip to the store.
Why the waste allowance is not optional
Every inside corner needs two 45 degree miters, and every outside corner needs two more, so each turn costs a little length in offcuts. Scarf joints along a long wall also consume material where two boards overlap at an angle. A 10 percent allowance absorbs these cuts plus the occasional split end or blade wander. Skip the allowance and you will buy the exact net run, which almost guarantees you finish a foot short on the final wall.
Piece length is a cutting decision, not just a price
The board length you choose shapes both the seam count and the offcut pile. Long 16 foot sticks let you trim a long wall in one clean run with no mid-wall joint, but they waste more when a wall is short. Shorter 8 foot boards are easier to handle and match to small walls, yet they multiply the number of joints you have to sand flush. Picking a length close to your longest walls tends to minimize both seams and scrap.
A quick sanity check before you buy
Before ordering, compare the linear feet figure against your longest single wall to make sure one board can span it, or plan a joint if it cannot. Then add one spare stick beyond the calculated count. That extra board covers a ruined miter and, just as importantly, leaves you a length of the exact same profile for a future repair. Trim profiles get discontinued, so a leftover stick in the garage is cheap insurance against a mismatched patch later.