How many inches is 1 micrometer?

0.0000393700787402 in, which is 1 divided by 25,400. These powers of ten scale the exact quantity; each displayed result rounds independently: 10 µm is 0.000393700787402 in, 100 µm is 0.00393700787402 in, 1,000 µm is 0.0393700787402 in and 1,000,000 µm is 39.3700787402 in. Going the other way, 25,400 µm is exactly 1 inch and 12,700 µm is exactly half of one.

What is the formula for micrometers to inches?

Inches = micrometres / 25,400, and micrometres = inches × 25,400 in the other direction, so 0.5 in is 12,700 µm and 2 in is 50,800 µm. An inch has been exactly 2.54 centimetres since the 1959 international agreement on the yard and the pound, and micro is the SI prefix for a millionth, so 25,400 µm to the inch is a definition that does not drift with time or country. Dividing by that exact figure is why 25,400 µm comes back as 1 and not as 0.99999. The Swap units button between the two boxes reverses the pair, so this page turns into an inches to micrometres converter without a reload.

How do I convert microns to thou or mils?

Divide by 25.4, because one thou is a thousandth of an inch and therefore exactly 25.4 µm. So 25.4 µm is 1 thou, 100 µm is 3.93700787402 thou and 1 µm is 0.0393700787402 thou. Thou, written mil on many drawings, is one of the uncommon units here: both dropdowns always list it, and the Show 7 more control in the readout, is what adds it to the list under the answer along with nanometre, furlong, astronomical unit, light year and parsec.

Is a micron the same as a micrometer?

Yes. Micron is the older name for one millionth of a metre, so a 5 micron filter rating and a 5 µm rating are the same number, both 0.000196850393701 in. SI dropped the name in 1967 and kept the unit, which is why filtration, coatings and 3D printing still say microns while a drawing carries the symbol µm. In the From box here the unit is listed as Micrometer (µm), and the arithmetic is identical whichever word you came for.

Is the decimal exact, or is it rounded?

The definition is exact: 1 µm is exactly 1/25,400 in. The denominator 25,400 = 2³ × 5² × 127 makes this unit factor repeat, displaying as 0.0000393700787402 in. An input can cancel its denominator: 25.4 µm gives exactly 0.001 in, 254 µm exactly 0.01 in and 25,400 µm exactly 1 in. Decimal-rational arithmetic preserves the written input; long outputs round beyond twelve significant digits even if they terminate.

What is 100 microns in inches, and what else does the list show?

100 µm is 0.00393700787402 in, just under four thou. The list under the answer holds every common length unit at the same time rather than one target at a time, so the same 100 µm also reads 0.1 mm, 0.01 cm, 0.0001 m, 1e-7 km, 0.000328083989501 ft and 0.000109361329834 yd. The From box accepts a typed exponent and thousands separators, so 2.54e4 and 25,400 are both read as 25,400 µm. Copy result copies the headline exactly as printed, without the separators.

Where does a micron to inch conversion come up?

For explicitly supplied length quantities, 50 µm displays as 0.00196850393701 in, 2.5 µm as 0.0000984251968504 in and 70 µm as 0.00275590551181 in. These may be stated thicknesses, wavelengths, dimensions or surface parameters. Conversion preserves the stated quantity and does not measure an object, validate a filter rating or determine which surface-finish parameter a source means.

Why does the page open on µm and inches when I last converted something else?

This focused page opens on Micrometer and Inch, while preserving the main converter’s saved unit pair. When storage is usable, a saved value and uncommon-unit preference can travel between pages. Its suffix must still match From. Valid deliberate scalar edits can save those fields after a short delay; invalid or incomplete drafts preserve the saved record. Unusable or conflicting records remain until you use Forget saved settings, which keeps the current conversion on screen. Your input and converted values are calculated in the browser and are not uploaded by the converter. The definitions arrive with the page, so conversion needs no external data lookup and keeps working offline after the page has loaded. The core conversion needs no account. Copy result copies the displayed headline without digit-grouping commas; each visible conversion row has its own Copy button. Displayed and copied values round to twelve significant digits. If native copying fails, a complete selectable summary identifies the input, selected pair and conventions and includes every unit in the category, including uncommon units.

Micrometers to Inches Converter

An inch is exactly 25.4 millimetres, which makes it exactly 25,400 micrometres, so micrometres to inches is one division: inches = µm / 25400. That puts 1 µm at 0.0000393700787402 in, 25.4 µm at exactly 0.001 in, 100 µm at 0.00393700787402 in, 500 µm at 0.0196850393701 in, 12,700 µm at exactly 0.5 in and 25,400 µm at exactly 1 in. Micron is the older name for the same unit, so a 5 micron rating converts identically, to 0.000196850393701 in. The 25.4 is a definition from the 1959 international yard and pound agreement rather than a measurement, the unit factor repeats while particular inputs can cancel its denominator, so answers print to twelve significant digits and fall back to exponential notation below 0.000001: 0.02 µm reads 7.87401574803e-7 in. This page opens the converter with Micrometer (µm) in the From box and Inch (in) in the To box, whatever pair you converted last, and the list under the answer carries the same length in millimetres, centimetres, metres, kilometres, inches, feet, yards, miles and nautical miles.

From

To0.0000393700787402

Category: Length

Base unit: meter

Uncommon units: Show 7 more

Feet, yards and miles use international definitions. A light year uses a 365.25-day Julian year; the parsec coefficient is approximate.

Results round to 12 significant digits using the listed unit definitions. Input must have a finite numeric magnitude and at most 512 significant digits. Type a single decimal or scientific number; a matching From unit suffix is accepted. Commas and grouped spaces separate thousands; decimal commas, fractions and compound measurements are refused.

1 µm in every length unit

Millimetermm
0.001
Centimetercm
0.0001
Meterm
0.000001
Kilometerkm
1e-9
Inchin
0.0000393700787402
Footft
0.00000328083989501
Yardyd
0.00000109361329834
Milemi
6.21371192237e-10
Nautical milenmi
5.39956803456e-10

Selectable complete conversion

Unit Converter — Length
Input: 1 (Micrometer, µm)
Result: 0.0000393700787402 in (Inch)
Displayed values round to 12 significant digits.
Feet, yards and miles use international definitions. A light year uses a 365.25-day Julian year; the parsec coefficient is approximate.
All other units:
Nanometer (nm): 1000
Millimeter (mm): 0.001
Centimeter (cm): 0.0001
Meter (m): 0.000001
Kilometer (km): 1e-9
Inch (in): 0.0000393700787402
Foot (ft): 0.00000328083989501
Yard (yd): 0.00000109361329834
Mile (mi): 6.21371192237e-10
Nautical mile (nmi): 5.39956803456e-10
Thou (mil): 0.0393700787402
Furlong (fur): 4.9709695379e-9
Astronomical unit (AU): 6.68458712227e-18
Light year (ly): 1.05700083402e-22
Parsec (pc): 3.24077928944e-23

Common questions

How many inches is 1 micrometer?: 0.0000393700787402 in, which is 1 divided by 25,400. These powers of ten scale the exact quantity; each displayed result rounds independently: 10 µm is 0.000393700787402 in, 100 µm is 0.00393700787402 in, 1,000 µm is 0.0393700787402 in and 1,000,000 µm is 39.3700787402 in. Going the other way, 25,400 µm is exactly 1 inch and 12,700 µm is exactly half of one.
What is the formula for micrometers to inches?: Inches = micrometres / 25,400, and micrometres = inches × 25,400 in the other direction, so 0.5 in is 12,700 µm and 2 in is 50,800 µm. An inch has been exactly 2.54 centimetres since the 1959 international agreement on the yard and the pound, and micro is the SI prefix for a millionth, so 25,400 µm to the inch is a definition that does not drift with time or country. Dividing by that exact figure is why 25,400 µm comes back as 1 and not as 0.99999. The Swap units button between the two boxes reverses the pair, so this page turns into an inches to micrometres converter without a reload.
How do I convert microns to thou or mils?: Divide by 25.4, because one thou is a thousandth of an inch and therefore exactly 25.4 µm. So 25.4 µm is 1 thou, 100 µm is 3.93700787402 thou and 1 µm is 0.0393700787402 thou. Thou, written mil on many drawings, is one of the uncommon units here: both dropdowns always list it, and the Show 7 more control in the readout, is what adds it to the list under the answer along with nanometre, furlong, astronomical unit, light year and parsec.
Is a micron the same as a micrometer?: Yes. Micron is the older name for one millionth of a metre, so a 5 micron filter rating and a 5 µm rating are the same number, both 0.000196850393701 in. SI dropped the name in 1967 and kept the unit, which is why filtration, coatings and 3D printing still say microns while a drawing carries the symbol µm. In the From box here the unit is listed as Micrometer (µm), and the arithmetic is identical whichever word you came for.
Is the decimal exact, or is it rounded?: The definition is exact: 1 µm is exactly 1/25,400 in. The denominator 25,400 = 2³ × 5² × 127 makes this unit factor repeat, displaying as 0.0000393700787402 in. An input can cancel its denominator: 25.4 µm gives exactly 0.001 in, 254 µm exactly 0.01 in and 25,400 µm exactly 1 in. Decimal-rational arithmetic preserves the written input; long outputs round beyond twelve significant digits even if they terminate.
What is 100 microns in inches, and what else does the list show?: 100 µm is 0.00393700787402 in, just under four thou. The list under the answer holds every common length unit at the same time rather than one target at a time, so the same 100 µm also reads 0.1 mm, 0.01 cm, 0.0001 m, 1e-7 km, 0.000328083989501 ft and 0.000109361329834 yd. The From box accepts a typed exponent and thousands separators, so 2.54e4 and 25,400 are both read as 25,400 µm. Copy result copies the headline exactly as printed, without the separators.
Where does a micron to inch conversion come up?: For explicitly supplied length quantities, 50 µm displays as 0.00196850393701 in, 2.5 µm as 0.0000984251968504 in and 70 µm as 0.00275590551181 in. These may be stated thicknesses, wavelengths, dimensions or surface parameters. Conversion preserves the stated quantity and does not measure an object, validate a filter rating or determine which surface-finish parameter a source means.
Why does the page open on µm and inches when I last converted something else?: This focused page opens on Micrometer and Inch, while preserving the main converter’s saved unit pair. When storage is usable, a saved value and uncommon-unit preference can travel between pages. Its suffix must still match From. Valid deliberate scalar edits can save those fields after a short delay; invalid or incomplete drafts preserve the saved record. Unusable or conflicting records remain until you use Forget saved settings, which keeps the current conversion on screen. Your input and converted values are calculated in the browser and are not uploaded by the converter. The definitions arrive with the page, so conversion needs no external data lookup and keeps working offline after the page has loaded. The core conversion needs no account. Copy result copies the displayed headline without digit-grouping commas; each visible conversion row has its own Copy button. Displayed and copied values round to twelve significant digits. If native copying fails, a complete selectable summary identifies the input, selected pair and conventions and includes every unit in the category, including uncommon units.

Results round to 12 significant digits using the listed unit conventions. Many factors are exact definitions; psi and parsec use rounded coefficients. Temperature includes scale offsets. Days and weeks are fixed-duration units, and unit conversion does not determine calendar dates, ambient pressure or a software label’s convention.