Room Area Calculator
Work out a room's floor area, including L-shaped rooms with a cut-out.
What is Room Area?
The floor area of a rectangular room — length times width — is the first number almost every material estimate needs: flooring, carpet, paint ceilings, rug sizing, furniture planning. Many rooms are not simple rectangles, so this page also subtracts a second rectangle (a stairwell, a chimney breast, an alcove) to give the true area.
How it works
The two dimensions are multiplied, and an optional cut-out rectangle is subtracted from the product. Both metric and imperial are shown — enter in either unit with the toggle — but the arithmetic runs in one system internally so a mixed-unit mistake cannot happen.
- Enter your input. Type or paste your input into the field above — the tool responds instantly.
- Review the result. Output updates live as you type. Everything runs entirely in your browser.
- Copy or download. Use the Copy button to grab the result, or Download to save it as a file.
Examples
Realistic sample
Type or paste any realistic input — the tool computes the result locally and instantly.
Common mistakes
Expecting a server round-trip
Nothing is uploaded — every tool in this category runs entirely in your browser.