Guides: area, land and how to measure it

By Rohit GaurLast updated October 8, 2026Report a mistake

Each guide answers one question properly: what the unit is, what it looks like drawn to scale, and where every number comes from. Where a calculator does the arithmetic, the guide links to it.

All guides

How to measure the square footage of a house
Outside the walls, finished space only, basements kept apart: the ANSI Z765 rules, with a worked example.
How big is an acre?
43,560 sq ft: a 208.7 ft square, 12 tennis courts, 90.75% of a football field.
How to calculate square footage
The short version: length × width, in feet, gives square feet — and every awkward room is just rectangles added together.