Light Year to Fermi Converter

Length Converter

31 units available

Decimals:

From

To

9.460730e+30

1 ly = 9.460730e+30 fm

Formula:

fm = ly × 9.460730e+30

With your value: 1 ly = 9.460730e+30 fm

How big is that?

Everyday references on a logarithmic scale, all expressed in light year so you can sanity-check the result.

Olympic pool (1/1.9e+14 your value)5.29e-15 ly

Football pitch (length) (1/9.0e+13 your value)1.11e-14 ly

Eiffel Tower (1/2.9e+13 your value)3.49e-14 ly

Burj Khalifa (1/1.1e+13 your value)8.75e-14 ly

Marathon (1/2.2e+11 your value)4.46e-12 ly

Your value1.00 ly

Other Light Year to Fermi conversions

2 ly to fm 3 ly to fm 4 ly to fm 5 ly to fm 6 ly to fm 7 ly to fm 8 ly to fm

Light Year to Fermi Conversion Table

Light Year (ly)	Fermi (fm)
0.5	4.730365e+30
1	9.460730e+30
2	1.892146e+31
5	4.730365e+31
10	9.460730e+31
15	1.419110e+32
20	1.892146e+32
25	2.365183e+32
50	4.730365e+32
100	9.460730e+32
250	2.365183e+33
500	4.730365e+33
1000	9.460730e+33

Fermi to Light Year Conversion Table

Fermi (fm)	Light Year (ly)
0.5	5.285004e-32
1	1.057001e-31
2	2.114002e-31
5	5.285004e-31
10	1.057001e-30
15	1.585501e-30
20	2.114002e-30
25	2.642502e-30
50	5.285004e-30
100	1.057001e-29
250	2.642502e-29
500	5.285004e-29
1000	1.057001e-28

Where these values come from

Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.

Light Year (ly)

Length

Exact conversion

A light-year is the distance light travels in one Julian year: 9 460 730 472 580 800 m exactly.

Source: IAU Resolution B2 (2012) — definition of the astronomical unit; IAU B2 (2015) nominal values

International Astronomical Union · Reviewed 2026-07-01

Fermi (fm)

Length

Exact conversion

Traceable to the metre, defined by fixing the speed of light in vacuum at 299 792 458 m/s. Imperial lengths derive from the 1959 international yard (0.9144 m exactly).

Source: BIPM, The International System of Units (SI), 9th edition, 2019 (updated 2024)

Bureau International des Poids et Mesures · Reviewed 2026-07-01

How to Convert Light Year to Fermi

To convert from Light Year (ly) to Fermi (fm), multiply the value by 9.460730e+30.

Formula: fm = ly × 9.460730e+30

Reverse: ly = fm × 1.057001e-31

Step-by-Step Example

Start with your value in Light Year. For example: 5 ly
Multiply by the conversion factor: 5 x 9.460730e+30
The result is: 4.730365e+31 fm

About Light Year

A light year is the distance light travels through a vacuum in one Julian year — exactly 9,460,730,472,580,800 metres. It is a unit of distance, not of time.

Fun Fact: Proxima Centauri, the nearest star to the Sun, sits about 4.25 light years away.

Common uses: astronomy, popular science, education.

About Fermi

The fermi (fm) is a unit of distance and length. One fermi equals 1.000000 × 10^-15 metres. UnitConvertLab converts it against every other length unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.

Common uses: length calculations, engineering and science, education.

Frequently Asked Questions

How many Fermi are in 1 Light Year?

There are exactly 9.460730e+30 Fermi in 1 Light Year. This means the conversion factor from Light Year to Fermi is 9.460730e+30.

What is the formula to convert Light Year to Fermi?

The formula to convert Light Year to Fermi is: fm = ly × 9.460730e+30. For example, to convert 10 Light Year to Fermi, you would multiply 10 by 9.460730e+30.

What is a Light Year?