Convert Inches to Millimeters
1 in = 25.4 mm
Conversion Table
| inches (in) | millimeters (mm) |
|---|---|
| 0.5 | 12.7 |
| 1 | 25.4 |
| 2 | 50.8 |
| 5 | 127 |
| 10 | 254 |
| 25 | 635 |
| 50 | 1270 |
| 100 | 2540 |
| 250 | 6350 |
| 500 | 12700 |
| 1000 | 25400 |
How to Convert inches to millimeters
To convert inches to millimeters, multiply the value by the conversion factor:
For example: 10 in = 254 mm
About inches and millimeters
The Conversion Formula
To convert inches to millimeters, multiply the value by the conversion factor: 1 in = 25.4 mm. For a worked example, suppose you need to convert 25 in to millimeters: 25 × 25.4 = 635 mm. To convert in the opposite direction, divide by 25.4, or equivalently multiply by 0.0393701.
About inches
The inch is a unit of length in the British imperial and United States customary systems. The word comes from the Latin 'uncia', meaning 'one-twelfth'. Traditionally defined as the width of a man's thumb or the length of three barleycorns, it is now precision-defined as 25.4 millimeters. It is the global standard for electronic display sizes (TVs, monitors, phones) and wheel rim diameters. inches are commonly used in Screen sizes (TVs, smartphones), Tire rim diameters, Paper sizes (Letter, Legal), and Plumbing pipe diameters, Rainfall in the US.
A US quarter is just under 1 inch in diameter.
About millimeters
The millimeter (mm) is the standard unit for engineering and manufacturing precision. Defined as one thousandth of a meter, it allows for accurate specifications without resorting to fractions. In the late 19th century, the adoption of the millimeter in industrial design helped standardize interchangeable parts, a key driver of modern mass production. It is also the standard for reporting rainfall in meteorology. millimeters are commonly used in Engineering blueprints, Smartphone dimensions, Jewelry sizing, and Medical instruments, Meteorology (rainfall).
A standard credit card is 0.76 mm thick.
When Would You Convert inches to millimeters?
Converting between inches and millimeters is one of the most common length conversions. You might need this conversion when working with international specifications, following instructions written for a different measurement system, or comparing values across different standards. Having the conversion factor (1 in = 25.4 mm) memorized or bookmarked can save time in professional and everyday contexts alike.