Square inches to square centimeters (in² to cm²) converter

What is a square inches to square centimeters converter?

A square inches to square centimeters converter is an online tool that translates an area written in square inches (in²) into its equivalent in square centimeters (cm²), and the other way around. The square inch belongs to the imperial and US customary systems, while the square centimeter is part of the metric system. Because the two systems are widely used in different parts of the world, being able to switch between them quickly is essential whenever drawings, product specifications, or material sizes cross borders.

One square inch is the area of a square whose sides each measure one inch, and one square centimeter is the area of a square whose sides each measure one centimeter. Since an inch is defined as exactly 2.54 centimeters, the area relationship follows directly from squaring that length factor.

How it works

Area scales with the square of the length unit. An inch equals 2.54 cm, so a square inch equals 2.54 × 2.54 = 6.4516 square centimeters. This value is exact, not rounded, because the inch-to-centimeter definition is exact.

To convert from square inches to square centimeters you multiply by 6.4516. To go the other way, from square centimeters to square inches, you divide by 6.4516 (equivalently, multiply by about 0.15500031). The converter on this page performs both directions at once: type a value into either field and the matching value appears in the other.

Formula

$\text{cm}^2 = \text{in}^2 \times 6.4516$

$\text{in}^2 = \text{cm}^2 \div 6.4516$

Square inches to square centimeters conversion table

Examples

Example 1: One square inch

Convert 1 in² to square centimeters. Multiply by the conversion factor:

$1 \text{ in}^2 \times 6.4516 = 6.4516 \text{ cm}^2$

So a single square inch covers 6.4516 cm².

Example 2: Ten square inches

A small label measures 10 square inches. Convert it to square centimeters:

$10 \text{ in}^2 \times 6.4516 = 64.516 \text{ cm}^2$

Example 3: One thousand square inches

A sheet of material has an area of 1000 in². In metric units this is:

$1000 \text{ in}^2 \times 6.4516 = 6451.6 \text{ cm}^2$

Example 4: Reverse conversion

If you know an area is 6.4516 cm² and want it in square inches, divide by the factor:

$6.4516 \text{ cm}^2 \div 6.4516 = 1 \text{ in}^2$

Notes

• The factor 6.4516 is exact because the inch is defined as exactly 2.54 cm; squaring 2.54 gives 6.4516 with no rounding.
• Do not confuse the area factor (6.4516) with the length factor (2.54). Lengths convert with 2.54, areas with its square.
• For very large or very small areas you may prefer different units; this converter also offers square meters and square miles in its menus.
• Keep all measurements in one system before adding or comparing areas to avoid mistakes.

Frequently asked questions

How many square centimeters are in one square inch?

One square inch equals exactly 6.4516 square centimeters.

How do I convert square centimeters back to square inches?

Divide the number of square centimeters by 6.4516, or multiply by about 0.155. For instance, 64.516 cm² ÷ 6.4516 = 10 in².

Why is the factor 6.4516 and not 2.54?

The value 2.54 converts lengths (inches to centimeters). Area uses two dimensions, so you square that factor: 2.54 × 2.54 = 6.4516.

How many square centimeters are in 10 square inches?

Multiply 10 by 6.4516 to get 64.516 square centimeters.

Is the conversion factor exact or approximate?

It is exact. Because the inch is defined as precisely 2.54 cm, the square inch is precisely 6.4516 cm².

What is 100 square inches in square centimeters?

100 in² × 6.4516 = 645.16 cm².