# Convert Square Millimeters to Square Inches

Enter the area in square millimeters below to get the value converted to square inches.

**Results in Square Inches:**

## How to Convert Square Millimeters to Square Inches

To convert a square millimeter measurement to a square inch measurement, multiply the area by the conversion ratio. One square millimeter is equal to 0.00155 square inches, so use this simple formula to convert:

The area in square inches is equal to the square millimeters multiplied by 0.00155.

**For example,**here's how to convert 5 square millimeters to square inches using the formula above.

Square millimeters and square inches are both units used to measure area. Keep reading to learn more about each unit of measure.

## Square Millimeters

One square millimeter is equal to the area of a square with edges that are 1 millimeter in length.

The square millimeter, or square millimetre, is a multiple of the square meter, which is the SI derived unit for area. In the metric system, "milli" is the prefix for 10^{-3}. A square millimeter is sometimes also referred to as a square mm. Square millimeters can be abbreviated as *sq mm*, and are also sometimes abbreviated as *mm²*. For example, 1 square millimeter can be written as 1 sq mm or 1 mm².

## Square Inches

One square inch is equal to the area of a square with sides that are 1 inch in length.

The square inch is a US customary and imperial unit of area. A square inch is sometimes also referred to as a square in. Square inches can be abbreviated as *sq in*, and are also sometimes abbreviated as *in²*. For example, 1 square inch can be written as 1 sq in or 1 in².

## Square Millimeter Measurements and Equivalent Square Inch Conversions

Square Millimeters | Square Inches |
---|---|

1 sq mm | 0.00155 sq in |

2 sq mm | 0.0031 sq in |

3 sq mm | 0.00465 sq in |

4 sq mm | 0.0062 sq in |

5 sq mm | 0.00775 sq in |

6 sq mm | 0.0093 sq in |

7 sq mm | 0.01085 sq in |

8 sq mm | 0.0124 sq in |

9 sq mm | 0.01395 sq in |

10 sq mm | 0.0155 sq in |

11 sq mm | 0.01705 sq in |

12 sq mm | 0.0186 sq in |

13 sq mm | 0.02015 sq in |

14 sq mm | 0.0217 sq in |

15 sq mm | 0.02325 sq in |

16 sq mm | 0.0248 sq in |

17 sq mm | 0.02635 sq in |

18 sq mm | 0.0279 sq in |

19 sq mm | 0.02945 sq in |

20 sq mm | 0.031 sq in |

21 sq mm | 0.03255 sq in |

22 sq mm | 0.0341 sq in |

23 sq mm | 0.03565 sq in |

24 sq mm | 0.0372 sq in |

25 sq mm | 0.03875 sq in |

26 sq mm | 0.0403 sq in |

27 sq mm | 0.04185 sq in |

28 sq mm | 0.0434 sq in |

29 sq mm | 0.04495 sq in |

30 sq mm | 0.0465 sq in |

31 sq mm | 0.04805 sq in |

32 sq mm | 0.0496 sq in |

33 sq mm | 0.05115 sq in |

34 sq mm | 0.0527 sq in |

35 sq mm | 0.05425 sq in |

36 sq mm | 0.0558 sq in |

37 sq mm | 0.05735 sq in |

38 sq mm | 0.0589 sq in |

39 sq mm | 0.06045 sq in |

40 sq mm | 0.062 sq in |

## More Square Millimeter Area Conversions

**US Customary**

- Convert to Square Miles
- 1 sq mm is equal to 3.861E-13 square miles
- Convert to Acres
- 1 sq mm is equal to 2.4711E-10 acres
- Convert to Square Yards
- 1 sq mm is equal to 1.196E-6 square yards
- Convert to Square Feet
- 1 sq mm is equal to 1.0764E-5 square feet

**SI Units**

- Convert to Square Kilometers
- 1 sq mm is equal to 1.0E-12 square kilometers
- Convert to Square Meters
- 1 sq mm is equal to 1.0E-6 square meters
- Convert to Square Centimeters
- 1 sq mm is equal to 0.01 square centimeters

**Other Metric Units**

- Convert to Hectares
- 1 sq mm is equal to 1.0E-10 hectares
- Convert to Ares
- 1 sq mm is equal to 1.0E-8 ares