Convert Metres (m) to Light Years (ly) | m in ly

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# Let's convert Metres (m) to Light Years (ly)

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

## Quick Reference for Converting Metres to Light Years

Formula
ly = m / 9.46055E+15
Quick Rough Maths
To get the Light Years, divide the number of Metres by 9460.6 trillion
Metres (m) in 1 Light Year
There are 9.46055E+15 Metres in 1 Light Year
Light Years (ly) in 1 Metre
There are 0 Light Years in 1 Metre

## Unit Information

Metre
/ˈmiːtə/
Symbol: m
Unit System: SI

### What is the Metre?

The metre (or meter; US spelling) is the SI base unit of length and uses the symbol m.

Originally defined in 1793 as one ten-millionth of the distance from the equator to the North Pole but was redefined in 1799 in terms of a prototyped metre bar (this bar was changed again in 1889).

In 1983 the current definition was adopted and it is now the most common unit in any property in the world and is used in thousands of formulae to describe countless characteristics.

Let's hear it for the metre!

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.