Square Inch to Square Millimeter Conversion (in² to mm²)

How Many Square Millimeter in a Square Inch?

There are 645.16 square millimeter in a square inch.
1 Square Inch is equal to 645.16 Square Millimeter.
1 in² = 645.16 mm²

Square Inch to Square Millimeter Conversions

Square Inch Definition

Used very often in the framework of the Imperial system, square inches are the units of area which represent a square-shaped area with one inch on each side. One square inch is equal to 6.4516 square centimeters and can be marked with the symbols of sq in or in². It is widely used primarily in architecture, engineering, construction, and other related areas requiring measuring of relatively small areas.

Square Millimeter Definition

A square millimeter is a unit of area used for measuring very small areas. The unit is used as a part of SI measurement system and has a symbol of mm². One square millimeter is the area that equals to 1/100^th of a square centimeter (or 0.01 cm²) or equals to 1/1000000^th of a square meter (1.0 x 10^-6 m²).

About in² to mm² Converter

This is a very easy to use square inch to square millimeter converter. First of all just type the square inch (in²) value in the text field of the conversion form to start converting in² to mm², then select the decimals value and finally hit convert button if auto calculation didn't work. Square Millimeter value will be converted automatically as you type.

The decimals value is the number of digits to be calculated or rounded of the result of square inch to square millimeter conversion.

You can also check the square inch to square millimeter conversion chart below, or go back to square inch to square millimeter converter to top.