How this calculator works
It adds up the four walls, leaves a gap for each doorway, and adds a waste allowance for miters, coped joints and short offcuts. Then it divides by the length of the pieces you are buying and rounds up.
Nails are figured at two per stud with studs 16″ apart, and caulk at about 55 feet per tube for a 3/16″ bead along the top edge.
run = 2 × (length + width) − 3 ft per doorway
pieces = run × (1 + waste) ÷ piece length, rounded up
caulk tubes = run ÷ 55 ft, rounded upWorked example
A 14′ × 12′ bedroom has 52 ft of wall. Leaving 3 ft open for the door gives 49 ft of baseboard. With 10% for cuts that is 53.9 ft, or 3.37 pieces of 16 ft, so the list buys 4 pieces (64 ft). One box of nails and one tube of caulk finish the job.
Tips before you buy
- Buy pieces at least as long as your longest wall when you can. A joint in the middle of a wall is harder to hide than a corner.
- Cope inside corners instead of mitering them. A coped joint stays tight when the walls move or are not quite square.
- Mark the studs on the wall with painter’s tape above where the trim goes before you start nailing.
- Paint or prime the trim before you install it, then fill nail holes and touch up once it is up. It is faster than cutting in along the floor.
Questions
- How do I measure for baseboard?
- Measure each wall at floor level and add them up, then subtract the width of each doorway, since baseboard stops at the door casing. Include closets if they will get trim. The calculator uses the room’s length and width and takes 3 ft off for each doorway.
- How much extra baseboard should I buy?
- Add about 10% for miters, coped corners and short offcuts that cannot be used. Rooms with many outside corners, bay windows or angled walls need 15% or more. You can change the allowance under Coverage and waste.
- Do I need shoe molding or quarter round?
- Add it when the baseboard cannot cover the expansion gap of a floating floor, or when the floor is uneven and leaves gaps under the baseboard. It runs the same length as the baseboard and is nailed to the baseboard, not the floor, so a floating floor can still move.
- What nails do I use for baseboard?
- Most baseboard is installed with 15 or 16 gauge finish nails long enough to pass through the trim and drywall and into the studs, often 2″ to 2½″ for typical trim. Thin shoe molding uses shorter 18 gauge brads.