Calculapedia

Baseboard Calculator

How much baseboard do you need? Enter your room size and doorways.

Room perimeter
With 10% waste
Estimated cost
Shop baseboard & trim →

How this calculator works

It adds up your room’s perimeter, subtracts 3 feet for each doorway opening, and adds 10% for miter cuts and waste at corners.

Worked example — a 12 ft × 12 ft room with 1 doorway:
Perimeter 48 − 3 = 45 ft × 1.10 = 50 linear feet.

Buy slightly long

Trim is sold in fixed lengths (8, 12, 16 ft). Buy lengths that minimize seams on your longest walls, and keep the offcuts for short runs.

Frequently asked questions

How do I measure for baseboard?

Add the length of every wall (the room perimeter), then subtract the width of each doorway.

How much extra trim should I buy?

About 10% to cover miter cuts and mistakes.

Planning a wall or paint project

Surface condition matters as much as area. Rough, porous, repaired, or strongly colored surfaces may need extra primer or paint. Check the coverage printed on the product you plan to use and account for trim, ceilings, openings, and a second coat where applicable.

How to use this estimate

Accuracy and limitations

Calculapedia provides educational planning estimates. It does not inspect your site, select products, guarantee quantities, or replace a contractor, engineer, architect, building official, or supplier. Confirm the final quantity and any safety or code requirements before buying or building.

Add this calculator to your site — free

Paste this code onto any web page (blog, forum, business site). It always shows the latest version and links back here.