Measure each room (width × length) and add them for total home square footage.
Average US home size: ~2,300 sq ft (2024).
Gross sq ft includes walls and all spaces; net sq ft is usable living area only.
This tool is most useful when you need a result you can trust without double-checking. It applies the correct formula automatically and handles edge cases that trip up manual calculation.
The most frequent error is using approximate inputs in a precise calculation and treating the result as if it were exact. The output is only as accurate as the inputs — imprecise measurements or estimated values produce imprecise results.
A freelancer calculates the exact number of working days between a project start and deadline, accounting for weekends and public holidays. The result tells them whether the timeline is achievable before accepting the brief — not after.
Multiply each room's width by length, then add all rooms together.
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