How to Use the Square Footage Calculator

Add a row per room with its own length and width — the total updates as rooms are added, which is the point once a whole floor plan doesn't fit one rectangle.

One rectangle's area is length times width. Most real floor plans aren't one rectangle — an L-shaped living room, a house with three bedrooms, a deck plus a shed — so this Square Footage Calculator lets you add as many rectangular sections as you need and sums them into one total.

Irregular shapes (anything with an angle, a bay window, a curve) need to be broken into rectangular pieces first — sketch the space, split it into boxes you can measure straight edges on, and enter each one as its own row here.