Convert Inch to Micrometer
Convert inches to micrometers instantly. 1 inch = 25400 micrometer — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Micrometer to Inch converter for the reverse conversion.
Units explained
Inch
An inch is an Imperial and US customary unit of length defined since 1959 as exactly 25.4 millimeters (0.0254 meters). It is still the standard small unit of length in the United States, the United Kingdom (informally), and a few other countries.
The inch derives from the Roman uncia (one-twelfth of a foot) and survived through Anglo-Saxon and medieval English measurement systems. Various definitions persisted regionally until the 1959 International Yard and Pound Agreement standardized the inch globally as exactly 25.4 mm.
Inches are used in the US and UK for body height, screen sizes (TVs, monitors, phones), tire sizes, plumbing, lumber, paper sizes (US Letter is 8.5 × 11 in), and most consumer product specifications in the United States.
Anglo-Saxon origin (predating 1066); standardized to 25.4 mm exactly by the International Yard and Pound Agreement of 1959, signed by the US, UK, Canada, Australia, New Zealand, and South Africa.
Micrometer
A micrometer (also called a micron) is a metric unit of length equal to one millionth of a meter (1×10⁻⁶ m). It is the standard unit for measuring microscopic dimensions in biology, materials science, and semiconductor manufacturing.
Defined alongside the meter when France adopted the metric system in 1795, using the SI prefix micro- (from Greek mikros, "small") to denote one-millionth.
Micrometers are used to measure cell sizes, bacteria, semiconductor process nodes, fiber diameters, dust particles, and wavelengths of infrared radiation. The diameter of a human hair is about 70 μm.
Defined in 1795 as part of the original French metric system; the name "micron" was officially deprecated by the BIPM in 1967 in favor of micrometer.
Inch to Micrometer conversion formula
The relationship between inches and micrometers:
To convert inches to micrometers, multiply the value in inches by 25400. To reverse, multiply micrometers by 3.937008e-5.
How to use this converter
Type a value into the calculator. The result in micrometers updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Micrometer to Inch converter for the reverse direction.
Step-by-step: convert inches to micrometers
- Write down the value in inches (in).
- Multiply that value by the factor 25400.
- The product is the equivalent value in micrometers (μm).
- To reverse, multiply the micrometer value by 3.937008e-5.
Worked examples
Example 1 — Convert 1 in to μm:
1 × 25400 = 25400 μm
Example 2 — Convert 100 in to μm:
100 × 25400 = 2540000 μm
Real-world example — Adjacent metric sub-units
One inch equals 1,000 micrometers. Engineers move between these scales constantly: PCB feature sizes in the larger unit, wire-bond diameters in the smaller.
1 in × 25400 = 25400 μm
Real-world example — Adjacent small-scale precision
One inch equals 1,000 micrometers — the standard sub-millimeter precision conversion that materials engineers use whenever they switch between bulk material thickness specs (larger unit) and surface-finish characteristics (smaller unit).
1 in × 25400 = 25400 μm
Inch to Micrometer conversion table
Standard reference values for converting inches to micrometers:
| Inch [in] | Micrometer [μm] |
|---|---|
| 0.01 | 254 |
| 0.1 | 2540 |
| 1 | 25400 |
| 2 | 50800 |
| 3 | 76200 |
| 4 | 101600 |
| 5 | 127000 |
| 10 | 254000 |
| 20 | 508000 |
| 30 | 762000 |
| 40 | 1016000 |
| 50 | 1270000 |
| 100 | 2540000 |
| 500 | 1.27e+7 |
| 1000 | 2.54e+7 |
Frequently asked questions
How many micrometers is 1 inch?
How do I convert inches to micrometers?
How do I convert micrometers back to inches?
How many micrometers is 100 inches?
Popular length unit conversions
Convert Inch to other length units
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Metric / SI (18 units)
Imperial / US Customary (26 units)
Nautical (1 units)
Astronomical (9 units)
Atomic / Physics (6 units)
Typographic (3 units)
Sources & references
Conversion factor (1 in = 25400 μm) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Hydrographic Organization — Resolution on the Nautical Mile
International authority that standardised the nautical mile at exactly 1852 m in 1929 — the value adopted worldwide for sea and air navigation.