Convert Mil to Nanometer
Convert mils to nanometers instantly. 1 mil = 25400 nanometer — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Nanometer to Mil converter for the reverse conversion.
Units explained
Mil
A mil (also called a thou) is an Imperial unit of length equal to one thousandth of an inch (1/1000 in = 0.0254 mm = 25.4 μm exactly). It is used in engineering, manufacturing, and materials specifications.
The mil is derived from the Latin mille, "thousand," denoting one-thousandth of an inch. Standardized in industrial use during the 19th-century rise of precision engineering.
Mils are used to specify thicknesses of plastic films, foils, paper, copper traces on printed circuit boards (PCBs), wire insulation, and paint coatings. A standard sheet of paper is about 4 mils thick.
Adopted in 19th-century engineering practice; the value (1/1000 in) became exact in 1959 when the inch was fixed at 25.4 mm via the International Yard and Pound Agreement. The British term is "thou"; American term is "mil".
Nanometer
A nanometer is a metric unit of length equal to one billionth of a meter (1×10⁻⁹ m). It is the standard unit for measuring atomic and molecular dimensions and is widely used in physics, chemistry, and electronics.
Defined using the SI prefix nano- (from Greek nanos, "dwarf") to denote one-billionth, adopted by the General Conference on Weights and Measures (CGPM) in 1960.
Nanometers are used to measure wavelengths of visible light (400–700 nm), semiconductor transistor sizes (currently 3–5 nm process nodes), DNA double helix width (2 nm), and atomic radii. The 2019 SI redefinition fixed the meter to the speed of light, making nanometer definitions exact to atomic precision.
SI prefix nano- adopted by the CGPM in 1960; nanometer became the standard unit for nanotechnology and optical wavelengths during the late 20th century.
Mil to Nanometer conversion formula
The relationship between mils and nanometers:
To convert mils to nanometers, multiply the value in mils by 25400. To reverse, multiply nanometers by 3.937008e-5.
How to use this converter
Type a value into the calculator. The result in nanometers updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Nanometer to Mil converter for the reverse direction.
Step-by-step: convert mils to nanometers
- Write down the value in mils (mil).
- Multiply that value by the factor 25400.
- The product is the equivalent value in nanometers (nm).
- To reverse, multiply the nanometer value by 3.937008e-5.
Worked examples
Example 1 — Convert 1 mil to nm:
1 × 25400 = 25400 nm
Example 2 — Convert 100 mil to nm:
100 × 25400 = 2540000 nm
Real-world example — From microns to sub-micron features
One mil equals one thousand nanometers — the conversion semiconductor designers do constantly when comparing mask feature dimensions to actual transistor gate lengths.
1 mil × 25400 = 25400 nm
Real-world example — Infrared to visible-spectrum mapping
A 10-mil thermal infrared wavelength corresponds to a much larger number in nanometers, the unit favoured for ultraviolet and visible-light specifications.
10 mil × 25400 = 254000 nm
Real-world example — Mid-micron to nanometer
3 mils equals 3,000 nanometers — useful when relating mid-infrared wavelengths (typically quoted in microns) to nanometer-scale visible-light wavelength tables.
3 mil × 25400 = 76200 nm
Mil to Nanometer conversion table
Standard reference values for converting mils to nanometers:
| Mil [mil] | Nanometer [nm] |
|---|---|
| 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 nanometers is 1 mil?
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Popular length unit conversions
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Metric / SI (7 units)
Imperial / US Customary (26 units)
Nautical (1 units)
Sources & references
Conversion factor (1 mil = 25400 nm) 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.