Square Inches Calculator

Use this square inches calculator to find the area of a rectangle measured in inches. Multiply length by width to get square inches, then divide by 144 to get square feet, since a square foot is 12 in. by 12 in. A 12 in. by 12 in. square is 144 sq in., or 1 sq ft.

Last reviewed September 2026Method & sources Report an error

Not to scale.

Area

144.000 sq in

Breakdown
Area	144.000 sq in
Area	1.000 sq ft

How to Calculate Square Inches

Area is length × width, both measured in inches. Dividing by 144 (12 × 12) converts the result to square feet.

Example: 12 in. × 12 in. square

A 12 in. × 12 in. square: 1. Area: 12 × 12 = 144 sq in. 2. In square feet: 144 ÷ 144 = 1 sq ft (a 12 in. × 12 in. tile is exactly 1 sq ft)

What Is Square Inches?

A square inches calculator finds the area of a small rectangle measured in inches. It is useful for a tile sample, a small panel, a piece of material, or any object too small to comfortably measure or picture in square feet.

Square Inches: Pros and Cons

Pros

Gives both square inches and square feet, useful since some small items are specified in one unit and larger areas in the other
Fine-grained input precision (to 1/8 in.), appropriate for smaller, more precisely-measured objects
A direct, exact conversion with no approximation

Cons

Assumes a simple rectangular shape. A circular or irregular small object needs a different formula
For a full room or larger area, the Square Footage calculator's feet-based inputs suit the job better than inches do
Doesn't handle volume. See the Cubic Inches calculator for a three-dimensional version

Frequently Asked Questions

How do I calculate square inches?

Multiply length by width, both in inches. A 12 in. × 12 in. square is 144 sq in.

How many square inches are in a square foot?

There are 144 square inches in a square foot. A foot is 12 inches, so a square foot is 12 in. × 12 in. = 144 sq in.

Why would I calculate area in square inches instead of square feet?

Square inches is more practical for small objects, such as a tile sample, a piece of trim, or a small panel. It also suits anything where square feet would be an awkwardly small fraction, like 0.08 sq ft instead of 12 sq in.

How do I convert square inches to square feet?

Divide by 144. 288 sq in. is 288 ÷ 144 = 2 sq ft.

Does this work for a non-rectangular shape?

No. This calculates a rectangle's area (length × width). A circular area needs π × radius², and other shapes need their own specific formula.

Measurement