RightSizeTools Practical sizing calculators
Geometry Basics

Square Footage Calculator

Enter the length and width of a room, wall, floor, yard, or project area. Use the unit switch if you want metric inputs and results.

Last updated: May 2026

Unit system Switch between U.S. customary and metric units. Your choice is remembered on other calculators.

Area measurements

Measure the longest side as length and the other side as width. For irregular spaces, break the area into rectangles and add them together.

Visual guide

Which measurement goes where?

Use the long horizontal side as length and the side-to-side dimension as width.

ft
ft
Advanced settings
%
Use this if you want a planning buffer for material ordering.

Buying and sizing notes

How to use this estimate

What this includes

  • The required inputs shown on this page
  • common planning assumptions
  • optional advanced adjustments where provided

What it does not include

  • site-specific professional design
  • local code approval
  • manufacturer-specific requirements
  • installation quality

Common mistakes

  • Leaving a required input at the default when your situation is different
  • ignoring product labels or ratings
  • treating the estimate as an exact final answer

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