How Much Flooring Do You Need? A Room-by-Room Guide

How to measure a room for flooring, why box coverage numbers vary, and how much extra to order so you don't run short mid-install.

Flooring is sold by the box, and each box covers a fixed square footage printed on the label — so the real question isn't "how big is my room" but "how many boxes does that area require, including the material lost to cuts."

Measuring correctly

Measure length and width at the widest points of the room, in feet, and multiply for square footage. For L-shaped or irregular rooms, split the space into rectangles, calculate each separately, and add the totals together rather than trying to average an odd shape.

Why you always order more than the exact area

Every install loses material to cuts at the edges of the room, and board or plank flooring loses more than tile does because full planks rarely fit a room's exact dimensions. A 10% waste factor is standard for a simple rectangular room; complex layouts, diagonal patterns, or rooms with lots of closets and corners typically need 15% or more.

Reading a coverage label correctly

A box labeled "22 sq ft per box" covers exactly that — divide your total area (with waste factor already added) by that number and round up, since you can't buy a partial box.

The Flooring Calculator takes your room dimensions and box coverage and returns the exact box count to buy, already accounting for waste.