Inch to Millimeter Conversion Calculator: Free Online Tool
Convert inches to millimeters with our free online length converter.
Inch to Millimeter Calculator
How to Use the Calculator:
- Enter the value you want to convert in the 'From' field (Inch).
- The converted value in Millimeter will appear automatically in the 'To' field.
- Use the dropdown menus to select different units within the Length category.
- Click the swap button (⇌) to reverse the conversion direction.
How to Convert Inch to Millimeter
Converting Inch to Millimeter involves multiplying the value by a specific conversion factor, as shown in the formula below.
Formula:
1 Inch = 25.4 millimetersExample Calculation:
Convert 10 inches: 10 × 25.4 = 254 millimeters
Disclaimer: For Reference Only
These conversion results are provided for informational purposes only. While we strive for accuracy, we make no guarantees regarding the precision of these results, especially for conversions involving extremely large or small numbers which may be subject to the inherent limitations of standard computer floating-point arithmetic.
Not for professional use. Results should be verified before use in any critical application. View our Terms of Service for more information.
What is a Inch and a Millimeter?
The inch is a unit of length in the British imperial and United States customary systems of measurement. It is defined as exactly 1/12 of a foot or 2.54 centimeters.
The millimeter is a unit of length in the metric system equal to one-thousandth of a meter (1/1000 m) or one-tenth of a centimeter (1/10 cm). It is used for very precise measurements.
Note: The Inch is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Millimeter belongs to the metric (SI) system.
History of the Inch and Millimeter
The inch has ancient origins, historically related to the width of a thumb or the length of three barleycorns laid end-to-end. Its definition was standardized internationally in 1959 based on the metric system (1 inch = 2.54 cm exactly).
Defined as a subunit of the meter within the original metric system, the millimeter provides a standard unit for fine measurements required in science, engineering, and manufacturing.
Common Uses for inches and millimeters
Explore the typical applications for both Inch (imperial/US) and Millimeter (metric) to understand their common contexts.
Common Uses for inches
- Everyday US Measurements: Everyday measurements in the US (e.g., height, paper size, screen sizes).
- US Construction: Construction and carpentry in the US.
- Apparel Sizing: Clothing sizes (e.g., waist size, inseam).
- US Meteorology: Measuring rainfall in the US.
- Engineering Components: Component sizes in some engineering fields.
Common Uses for millimeters
- Engineering & Machining: Precise engineering and machining measurements.
- Technical Design: Technical drawings and specifications.
- Electronics: Measuring small electronic components or wire gauges.
- Meteorology: Measuring rainfall amounts.
- Science: Scientific measurements requiring high precision (e.g., microscopy).
Frequently Asked Questions
Questions About Inch (in)
How many inches are in a foot?
There are exactly 12 inches (in) in 1 foot (ft).
How many centimeters are in an inch?
There are exactly 2.54 centimeters (cm) in 1 inch (in).
Where is the inch primarily used?
The inch is the standard unit for many everyday length measurements in the United States. It is also used to some extent in Canada and the UK, though metric is more common officially.
About Millimeter (mm)
How many millimeters are in a centimeter?
There are 10 millimeters (mm) in 1 centimeter (cm).
How many millimeters are in a meter?
There are 1,000 millimeters (mm) in 1 meter (m).
What does 'milli' mean in millimeter?
The prefix 'milli' denotes one-thousandth (1/1000).
Conversion Table: Inch to Millimeter
| Inch (in) | Millimeter (mm) |
|---|---|
| 1 | 25.4 |
| 5 | 127 |
| 10 | 254 |
| 25 | 635 |
| 50 | 1,270 |
| 100 | 2,540 |
| 500 | 12,700 |
| 1,000 | 25,400 |