Convert Inch to Millimeter Online

Inch (in)

Millimeter (mm)

About Inch to Millimeter Conversion

This converter converts Inch (in) to Millimeter (mm). One Inch (in) equals 25.4 Millimeter (mm).

Formula:

1 Inch (in) = 25.4 Millimeter (mm)

Example:

1 in = 25.4 mm

2 in = 50.8 mm

Inch (in) to Millimeter (mm) Conversion

A clear guide to converting Inch into Millimeter. Includes numeric examples, formulas, and a breakdown of where this conversion appears in science, engineering, and daily applications.

Conversion Formula

Millimeter = Inch × 25.4

To convert Inch (in) to Millimeter (mm), multiply the value by 25.4. This factor is obtained by comparing their exact meter definitions.

Worked Example

Convert 1 in to mm.

Step 1: Write the formula: mm = in × 25.4
Step 2: Substitute: 1 × 25.4
Step 3: Result: 25.4 mm

So, 1 in = 25.4 mm.

About the Units

Inch (in)

One Inch (in) equals 25.4 Millimeter (mm)

A widely used unit across scientific, engineering, and measurement contexts.

Millimeter (mm)

One Millimeter (mm) equals 0.03937 Inch (in)

Common in precision engineering and laboratory measurement.

Where This Conversion Is Used

Converting values from Inch to Millimeter for engineering or scientific workflows.
Used when normalizing mixed-unit datasets requiring consistent Millimeter representation.
Applied when comparing different measurement systems across tools and documents.
Common in carpentry, architecture, and traditional US/UK measurement scenarios.

Frequently Asked Questions

How many Millimeter (mm) are in 1 Inch (in)?

1 in = 25.4 mm.

What is the formula for converting Inch (in) to Millimeter (mm)?

Multiply the in value by 25.4.

Can I reverse the conversion?

Yes. 1 mm = 0.03937 in.

Conclusion

By applying the conversion factor shown above, you can reliably convert Inch (in) to Millimeter (mm) for use in scientific analysis, engineering calculations, academic work, or daily measurements.

Quick Links for Unit Converters

Convert Inch to Other Units

Inch to Foot

1 in = 0.08333333333333333 ft

1 Inch (in) = 0.08333333333333333 Foot (ft)

1 inch equals 0.08333333333333333 foot.

Inch to Feet

1 in = 0.08333333333333333 ft

1 Inch (in) = 0.08333333333333333 Feet (ft)

1 inch equals 0.08333333333333333 feet.

Inch to Centimeter

1 in = 2.54 cm

1 Inch (in) = 2.54 Centimeters (cm)

1 inch equals 2.54 centimeters.

Inch to Meter

1 in = 0.0254 m

1 Inch (in) = 0.0254 Meter (m)

1 inch equals 0.0254 meter.

Inch to Kilometer

1 in = 0.000025399999999999997 km

1 Inch (in) = 0.000025399999999999997 Kilometer (km)

1 inch equals 0.000025399999999999997 kilometer.

Inch to Millimeter

1 in = 25.4 mm

1 Inch (in) = 25.4 Millimeters (mm)

1 inch equals 25.4 millimeters.

Inch to Yard

1 in = 0.027777777777777776 yd

1 Inch (in) = 0.027777777777777776 Yard (yd)

1 inch equals 0.027777777777777776 yard.

Inch to Yoctometer

1 in = 2.54e+22 ym

1 Inch (in) = 2.54e+22 Yoctometers (ym)

1 inch equals 2.54e+22 yoctometers.

Inch to Zeptometer

1 in = 25400000000000000000 zm

1 Inch (in) = 25400000000000000000 Zeptometers (zm)

1 inch equals 25400000000000000000 zeptometers.

Inch to Attometer

1 in = 25399999999999996 am

1 Inch (in) = 25399999999999996 Attometers (am)

1 inch equals 25399999999999996 attometers.

Inch to Femtometer

1 in = 25399999999999.996 fm

1 Inch (in) = 25399999999999.996 Femtometers (fm)

1 inch equals 25399999999999.996 femtometers.

Inch to Picometer

1 in = 25400000000 pm

1 Inch (in) = 25400000000 Picometers (pm)

1 inch equals 25400000000 picometers.

Inch to Nanometer

1 in = 25399999.999999996 nm

1 Inch (in) = 25399999.999999996 Nanometers (nm)

1 inch equals 25399999.999999996 nanometers.

Inch to Micrometer

1 in = 25400 µm

1 Inch (in) = 25400 Micrometers (µm)

1 inch equals 25400 micrometers.

Inch to Decimeter

1 in = 0.25399999999999995 dm

1 Inch (in) = 0.25399999999999995 Decimeter (dm)

1 inch equals 0.25399999999999995 decimeter.

Inch to Decameter

1 in = 0.0025399999999999997 dam

1 Inch (in) = 0.0025399999999999997 Decameter (dam)

1 inch equals 0.0025399999999999997 decameter.

Inch to Hectometer

1 in = 0.000254 hm

1 Inch (in) = 0.000254 Hectometer (hm)

1 inch equals 0.000254 hectometer.

Inch to Megameter

1 in = 2.54e-8 Mm

1 Inch (in) = 2.54e-8 Megameter (Mm)

1 inch equals 2.54e-8 megameter.

Inch to Gigameter

1 in = 2.5399999999999998e-11 Gm

1 Inch (in) = 2.5399999999999998e-11 Gigameter (Gm)

1 inch equals 2.5399999999999998e-11 gigameter.

Inch to Terameter

1 in = 2.5399999999999998e-14 Tm

1 Inch (in) = 2.5399999999999998e-14 Terameter (Tm)

1 inch equals 2.5399999999999998e-14 terameter.

Inch to Petameter

1 in = 2.54e-17 Pm

1 Inch (in) = 2.54e-17 Petameter (Pm)

1 inch equals 2.54e-17 petameter.

Inch to Exameter

1 in = 2.5399999999999998e-20 Em

1 Inch (in) = 2.5399999999999998e-20 Exameter (Em)

1 inch equals 2.5399999999999998e-20 exameter.

Inch to Zettameter

1 in = 2.54e-23 Zm

1 Inch (in) = 2.54e-23 Zettameter (Zm)

1 inch equals 2.54e-23 zettameter.

Inch to Yottameter

1 in = 2.54e-26 Ym

1 Inch (in) = 2.54e-26 Yottameter (Ym)

1 inch equals 2.54e-26 yottameter.

Inch to Cubit

1 in = 0.05555555555555555 cubit

1 Inch (in) = 0.05555555555555555 Cubit (cubit)

1 inch equals 0.05555555555555555 cubit.

Inch to Span

1 in = 0.1111111111111111 span

1 Inch (in) = 0.1111111111111111 Span (span)

1 inch equals 0.1111111111111111 span.

Inch to Hand

1 in = 0.25 hh

1 Inch (in) = 0.25 Hand (hh)

1 inch equals 0.25 hand.

Inch to Palm

1 in = 0.3333333333333333 palm

1 Inch (in) = 0.3333333333333333 Palm (palm)

1 inch equals 0.3333333333333333 palm.

Inch to Digit

1 in = 1.3333333333333333 digit

1 Inch (in) = 1.3333333333333333 Digits (digit)

1 inch equals 1.3333333333333333 digits.

Inch to Link

1 in = 0.12626262626262624 link

1 Inch (in) = 0.12626262626262624 Link (link)

1 inch equals 0.12626262626262624 link.

Inch to Ell

1 in = 0.02222222222222222 ell

1 Inch (in) = 0.02222222222222222 Ell (ell)

1 inch equals 0.02222222222222222 ell.

Inch to Barleycorn

1 in = 2.998819362455726 barleycorn

1 Inch (in) = 2.998819362455726 Barleycorns (barleycorn)

1 inch equals 2.998819362455726 barleycorns.

Inch to Astronomical Unit

1 in = 1.6978851290561852e-13 AU

1 Inch (in) = 1.6978851290561852e-13 Astronomical Unit (AU)

1 inch equals 1.6978851290561852e-13 Astronomicalunit.

Inch to Light-Second

1 in = 8.472528018033061e-11 ls

1 Inch (in) = 8.472528018033061e-11 Light-Second (ls)

1 inch equals 8.472528018033061e-11 Light-Second.

Inch to Light-Minute

1 in = 1.4120880030055102e-12 lm

1 Inch (in) = 1.4120880030055102e-12 Light-Minute (lm)

1 inch equals 1.4120880030055102e-12 Light-Minute.

Inch to Light-Hour

1 in = 2.3534800045730524e-14 lh

1 Inch (in) = 2.3534800045730524e-14 Light-Hour (lh)

1 inch equals 2.3534800045730524e-14 Light-Hour.

Inch to Light-Day

1 in = 9.80616668799257e-16 ld

1 Inch (in) = 9.80616668799257e-16 Light-Day (ld)

1 inch equals 9.80616668799257e-16 Light-Day.

Inch to Light-Year

1 in = 2.684782118422523e-18 ly

1 Inch (in) = 2.684782118422523e-18 Light-Year (ly)

1 inch equals 2.684782118422523e-18 Light-Year.

Inch to Parsec

1 in = 8.231579395188679e-19 pc

1 Inch (in) = 8.231579395188679e-19 Parsec (pc)

1 inch equals 8.231579395188679e-19 Parsec.

Inch to Kiloparsec

1 in = 8.23157939518868e-22 kpc

1 Inch (in) = 8.23157939518868e-22 Kiloparsec (kpc)

1 inch equals 8.23157939518868e-22 Kiloparsec.

Inch to Megaparsec

1 in = 8.231579395188679e-25 Mpc

1 Inch (in) = 8.231579395188679e-25 Megaparsec (Mpc)

1 inch equals 8.231579395188679e-25 Megaparsec.

Inch to Gigaparsec

1 in = 8.23157939518868e-28 Gpc

1 Inch (in) = 8.23157939518868e-28 Gigaparsec (Gpc)

1 inch equals 8.23157939518868e-28 Gigaparsec.

Inch to Nautical Mile

1 in = 0.000013714902807775378 NM

1 Inch (in) = 0.000013714902807775378 Nautical Mile (NM)

1 inch equals 0.000013714902807775378 Nautical Mile.

Inch to Fathom

1 in = 0.013888888888888888 ftm

1 Inch (in) = 0.013888888888888888 Fathom (ftm)

1 inch equals 0.013888888888888888 fathom.

Inch to Cable Length

1 in = 0.00011574074074074075 cable

1 Inch (in) = 0.00011574074074074075 Cable Length (cable)

1 inch equals 0.00011574074074074075 Cable Length .

Inch to Nautical League

1 in = 0.0000045716342692584595 NL

1 Inch (in) = 0.0000045716342692584595 Nautical League (NL)

1 inch equals 0.0000045716342692584595 Nautical League.

Inch to Thou

1 in = 999.9999999999999 mil

1 Inch (in) = 999.9999999999999 Thous (mil)

1 inch equals 999.9999999999999 thous.

Inch to Rod

1 in = 0.00505050505050505 rd

1 Inch (in) = 0.00505050505050505 Rod (rd)

1 inch equals 0.00505050505050505 rod.

Inch to Chain

1 in = 0.0012626262626262625 ch

1 Inch (in) = 0.0012626262626262625 Chain (ch)

1 inch equals 0.0012626262626262625 chain.

Inch to Furlong

1 in = 0.00012626262626262626 fur

1 Inch (in) = 0.00012626262626262626 Furlong (fur)

1 inch equals 0.00012626262626262626 furlong.

Inch to Mile

1 in = 0.000015782828282828283 mi

1 Inch (in) = 0.000015782828282828283 Mile (mi)

1 inch equals 0.000015782828282828283 mile.

Inch to League

1 in = 0.00000526094276094276 lea

1 Inch (in) = 0.00000526094276094276 League (lea)

1 inch equals 0.00000526094276094276 league.

Convert Millimeter to Other Units

Millimeter to Inch

1 mm = 0.03937007874015748 in

1 Millimeter (mm) = 0.03937007874015748 Inch (in)

1 millimeter equals 0.03937007874015748 inch.

Millimeter to Foot

1 mm = 0.0032808398950131233 ft

1 Millimeter (mm) = 0.0032808398950131233 Foot (ft)

1 millimeter equals 0.0032808398950131233 foot.

Millimeter to Feet

1 mm = 0.0032808398950131233 ft

1 Millimeter (mm) = 0.0032808398950131233 Feet (ft)

1 millimeter equals 0.0032808398950131233 feet.

Millimeter to Centimeter

1 mm = 0.1 cm

1 Millimeter (mm) = 0.1 Centimeter (cm)

1 millimeter equals 0.1 centimeter.

Millimeter to Meter

1 mm = 0.001 m

1 Millimeter (mm) = 0.001 Meter (m)

1 millimeter equals 0.001 meter.

Millimeter to Kilometer

1 mm = 0.000001 km

1 Millimeter (mm) = 0.000001 Kilometer (km)

1 millimeter equals 0.000001 kilometer.

Millimeter to Yard

1 mm = 0.0010936132983377078 yd

1 Millimeter (mm) = 0.0010936132983377078 Yard (yd)

1 millimeter equals 0.0010936132983377078 yard.

Millimeter to Yoctometer

1 mm = 1.0000000000000001e+21 ym

1 Millimeter (mm) = 1.0000000000000001e+21 Yoctometers (ym)

1 millimeter equals 1.0000000000000001e+21 yoctometers.

Millimeter to Zeptometer

1 mm = 1000000000000000100 zm

1 Millimeter (mm) = 1000000000000000100 Zeptometers (zm)

1 millimeter equals 1000000000000000100 zeptometers.

Millimeter to Attometer

1 mm = 1000000000000000 am

1 Millimeter (mm) = 1000000000000000 Attometers (am)

1 millimeter equals 1000000000000000 attometers.

Millimeter to Femtometer

1 mm = 1000000000000 fm

1 Millimeter (mm) = 1000000000000 Femtometers (fm)

1 millimeter equals 1000000000000 femtometers.

Millimeter to Picometer

1 mm = 1000000000 pm

1 Millimeter (mm) = 1000000000 Picometers (pm)

1 millimeter equals 1000000000 picometers.

Millimeter to Nanometer

1 mm = 1000000 nm

1 Millimeter (mm) = 1000000 Nanometers (nm)

1 millimeter equals 1000000 nanometers.

Millimeter to Micrometer

1 mm = 1000.0000000000001 µm

1 Millimeter (mm) = 1000.0000000000001 Micrometers (µm)

1 millimeter equals 1000.0000000000001 micrometers.

Millimeter to Decimeter

1 mm = 0.01 dm

1 Millimeter (mm) = 0.01 Decimeter (dm)

1 millimeter equals 0.01 decimeter.

Millimeter to Decameter

1 mm = 0.0001 dam

1 Millimeter (mm) = 0.0001 Decameter (dam)

1 millimeter equals 0.0001 decameter.

Millimeter to Hectometer

1 mm = 0.00001 hm

1 Millimeter (mm) = 0.00001 Hectometer (hm)

1 millimeter equals 0.00001 hectometer.

Millimeter to Megameter

1 mm = 1e-9 Mm

1 Millimeter (mm) = 1e-9 Megameter (Mm)

1 millimeter equals 1e-9 megameter.

Millimeter to Gigameter

1 mm = 1e-12 Gm

1 Millimeter (mm) = 1e-12 Gigameter (Gm)

1 millimeter equals 1e-12 gigameter.

Millimeter to Terameter

1 mm = 1e-15 Tm

1 Millimeter (mm) = 1e-15 Terameter (Tm)

1 millimeter equals 1e-15 terameter.

Millimeter to Petameter

1 mm = 1e-18 Pm

1 Millimeter (mm) = 1e-18 Petameter (Pm)

1 millimeter equals 1e-18 petameter.

Millimeter to Exameter

1 mm = 1.0000000000000001e-21 Em

1 Millimeter (mm) = 1.0000000000000001e-21 Exameter (Em)

1 millimeter equals 1.0000000000000001e-21 exameter.

Millimeter to Zettameter

1 mm = 1.0000000000000001e-24 Zm

1 Millimeter (mm) = 1.0000000000000001e-24 Zettameter (Zm)

1 millimeter equals 1.0000000000000001e-24 zettameter.

Millimeter to Yottameter

1 mm = 1e-27 Ym

1 Millimeter (mm) = 1e-27 Yottameter (Ym)

1 millimeter equals 1e-27 yottameter.

Millimeter to Cubit

1 mm = 0.0021872265966754157 cubit

1 Millimeter (mm) = 0.0021872265966754157 Cubit (cubit)

1 millimeter equals 0.0021872265966754157 cubit.

Millimeter to Span

1 mm = 0.004374453193350831 span

1 Millimeter (mm) = 0.004374453193350831 Span (span)

1 millimeter equals 0.004374453193350831 span.

Millimeter to Hand

1 mm = 0.00984251968503937 hh

1 Millimeter (mm) = 0.00984251968503937 Hand (hh)

1 millimeter equals 0.00984251968503937 hand.

Millimeter to Palm

1 mm = 0.013123359580052493 palm

1 Millimeter (mm) = 0.013123359580052493 Palm (palm)

1 millimeter equals 0.013123359580052493 palm.

Millimeter to Digit

1 mm = 0.05249343832020997 digit

1 Millimeter (mm) = 0.05249343832020997 Digit (digit)

1 millimeter equals 0.05249343832020997 digit.

Millimeter to Link

1 mm = 0.004970969537898671 link

1 Millimeter (mm) = 0.004970969537898671 Link (link)

1 millimeter equals 0.004970969537898671 link.

Millimeter to Ell

1 mm = 0.0008748906386701663 ell

1 Millimeter (mm) = 0.0008748906386701663 Ell (ell)

1 millimeter equals 0.0008748906386701663 ell.

Millimeter to Barleycorn

1 mm = 0.1180637544273908 barleycorn

1 Millimeter (mm) = 0.1180637544273908 Barleycorn (barleycorn)

1 millimeter equals 0.1180637544273908 barleycorn.

Millimeter to Astronomical Unit

1 mm = 6.684587122268446e-15 AU

1 Millimeter (mm) = 6.684587122268446e-15 Astronomical Unit (AU)

1 millimeter equals 6.684587122268446e-15 Astronomicalunit.

Millimeter to Light-Second

1 mm = 3.3356409519815207e-12 ls

1 Millimeter (mm) = 3.3356409519815207e-12 Light-Second (ls)

1 millimeter equals 3.3356409519815207e-12 Light-Second.

Millimeter to Light-Minute

1 mm = 5.559401586635868e-14 lm

1 Millimeter (mm) = 5.559401586635868e-14 Light-Minute (lm)

1 millimeter equals 5.559401586635868e-14 Light-Minute.

Millimeter to Light-Hour

1 mm = 9.265669309342728e-16 lh

1 Millimeter (mm) = 9.265669309342728e-16 Light-Hour (lh)

1 millimeter equals 9.265669309342728e-16 Light-Hour.

Millimeter to Light-Day

1 mm = 3.860695546453768e-17 ld

1 Millimeter (mm) = 3.860695546453768e-17 Light-Day (ld)

1 millimeter equals 3.860695546453768e-17 Light-Day.

Millimeter to Light-Year

1 mm = 1.0570008340246155e-19 ly

1 Millimeter (mm) = 1.0570008340246155e-19 Light-Year (ly)

1 millimeter equals 1.0570008340246155e-19 Light-Year.

Millimeter to Parsec

1 mm = 3.2407792894443624e-20 pc

1 Millimeter (mm) = 3.2407792894443624e-20 Parsec (pc)

1 millimeter equals 3.2407792894443624e-20 Parsec.

Millimeter to Kiloparsec

1 mm = 3.2407792894443625e-23 kpc

1 Millimeter (mm) = 3.2407792894443625e-23 Kiloparsec (kpc)

1 millimeter equals 3.2407792894443625e-23 Kiloparsec.

Millimeter to Megaparsec

1 mm = 3.240779289444362e-26 Mpc

1 Millimeter (mm) = 3.240779289444362e-26 Megaparsec (Mpc)

1 millimeter equals 3.240779289444362e-26 Megaparsec.

Millimeter to Gigaparsec

1 mm = 3.2407792894443624e-29 Gpc

1 Millimeter (mm) = 3.2407792894443624e-29 Gigaparsec (Gpc)

1 millimeter equals 3.2407792894443624e-29 Gigaparsec.

Millimeter to Nautical Mile

1 mm = 5.399568034557235e-7 NM

1 Millimeter (mm) = 5.399568034557235e-7 Nautical Mile (NM)

1 millimeter equals 5.399568034557235e-7 Nautical Mile.

Millimeter to Fathom

1 mm = 0.0005468066491688539 ftm

1 Millimeter (mm) = 0.0005468066491688539 Fathom (ftm)

1 millimeter equals 0.0005468066491688539 fathom.

Millimeter to Cable Length

1 mm = 0.000004556722076407116 cable

1 Millimeter (mm) = 0.000004556722076407116 Cable Length (cable)

1 millimeter equals 0.000004556722076407116 Cable Length .

Millimeter to Nautical League

1 mm = 1.7998560115190786e-7 NL

1 Millimeter (mm) = 1.7998560115190786e-7 Nautical League (NL)

1 millimeter equals 1.7998560115190786e-7 Nautical League.

Millimeter to Thou

1 mm = 39.37007874015748 mil

1 Millimeter (mm) = 39.37007874015748 Thous (mil)

1 millimeter equals 39.37007874015748 thous.

Millimeter to Rod

1 mm = 0.00019883878151594686 rd

1 Millimeter (mm) = 0.00019883878151594686 Rod (rd)

1 millimeter equals 0.00019883878151594686 rod.

Millimeter to Chain

1 mm = 0.000049709695378986714 ch

1 Millimeter (mm) = 0.000049709695378986714 Chain (ch)

1 millimeter equals 0.000049709695378986714 chain.

Millimeter to Furlong

1 mm = 0.000004970969537898672 fur

1 Millimeter (mm) = 0.000004970969537898672 Furlong (fur)

1 millimeter equals 0.000004970969537898672 furlong.

Millimeter to Mile

1 mm = 6.21371192237334e-7 mi

1 Millimeter (mm) = 6.21371192237334e-7 Mile (mi)

1 millimeter equals 6.21371192237334e-7 mile.

Millimeter to League

1 mm = 2.07123730745778e-7 lea

1 Millimeter (mm) = 2.07123730745778e-7 League (lea)

1 millimeter equals 2.07123730745778e-7 league.