Convert Millimetres (mm) to Light Years (ly) | mm in ly

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Let's convert Millimetres (mm) to Light Years (ly)

This quick and easy calculator will convert Millimetres (mm) to Light Years (ly) and show formula, brief history on the units and quick maths for the conversion.

Enter Millimetres to convert to Light Years


Quick Reference for Converting Millimetres to Light Years

Formula
ly = mm / 9.46055E+18
Quick Rough Maths
To get the Light Years, divide the number of Millimetres by 9460550 trillion
Millimetres (mm) in 1 Light Year
There are 9.46055E+18 Millimetres in 1 Light Year
Light Years (ly) in 1 Millimetre
There are 0 Light Years in 1 Millimetre

Unit Information

Millimetre
/ˈmɪlɪmiːtə/
Symbol: mm
Unit System: SI

What is the Millimetre?

The millimetre (American spelling millimeter) is a unit of length and is a multiple of the SI unit metre. It uses the symbol mm.

There are 1000 mm in 1 m and 10 mm in 1 cm. From this one can derive that there are 0.03937 in.

The millimetre is sometimes verbally abbreviated to 'mil' - which can cause confusion in the US as there is a unit there that means thousandth of an inch.

Light Year
/lʌɪt jɪə,jəː/
Symbol: ly
Unit System: Astronomical System of Units

What is the Light Year?

The light year is a unit of length in the Astronomical system of units. It uses the symbol ly.

Often confused with a unit of time as it contains the word "year", it is actually defined by the International Astronomical Union (IAU) as the amount of distance that light travels in a vacuum in one Julian year (365.25 days).

Using the speed of light (299,792,458 m/s or 'c') and the Julian year (as apposed to the Gregorian year which is 365.2425 days), we can equivalate 1 light year as 9,460,730,472,580,800 metres or ≈ 9.46 trillion kilometres.


Conversion Tables for Millimetres (mm) to Light Years (ly)