Fermi to Kilometer Converter

Length Converter

31 units available

Decimals:

From

To

1.000000e-18

1 fm = 1.000000e-18 km

Formula:

km = fm × 1.000000e-18

With your value: 1 fm = 1.000000e-18 km

How big is that?

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

Your value1.00 fm

Grain of sand (5.0e+11× your value)5.00e+11 fm

Credit card (long side) (8.6e+13× your value)8.56e+13 fm

A4 sheet (height) (3.0e+14× your value)2.97e+14 fm

Adult stride (7.5e+14× your value)7.50e+14 fm

Standard door height (2.0e+15× your value)2.00e+15 fm

Other Fermi to Kilometer conversions

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

Fermi to Kilometer Conversion Table

Fermi (fm)	Kilometer (km)
0.5	5.000000e-19
1	1.000000e-18
2	2.000000e-18
5	5.000000e-18
10	1.000000e-17
15	1.500000e-17
20	2.000000e-17
25	2.500000e-17
50	5.000000e-17
100	1.000000e-16
250	2.500000e-16
500	5.000000e-16
1000	1.000000e-15

Kilometer to Fermi Conversion Table

Kilometer (km)	Fermi (fm)
0.5	5.000000e+17
1	1.000000e+18
2	2.000000e+18
5	5.000000e+18
10	1.000000e+19
15	1.500000e+19
20	2.000000e+19
25	2.500000e+19
50	5.000000e+19
100	1.000000e+20
250	2.500000e+20
500	5.000000e+20
1000	1.000000e+21

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.

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

Kilometer (km)

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 Fermi to Kilometer

To convert from Fermi (fm) to Kilometer (km), multiply the value by 1.000000e-18.

Formula: km = fm × 1.000000e-18

Reverse: fm = km × 1.000000e+18

Step-by-Step Example

Start with your value in Fermi. For example: 5 fm
Multiply by the conversion factor: 5 x 1.000000e-18
The result is: 5.000000e-18 km

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.

About Kilometer

The kilometer equals 1,000 meters and is the standard unit for measuring distances between geographical locations in most countries.

Fun Fact: The circumference of Earth is approximately 40,075 km.

Common uses: road distances, geography, running.

Frequently Asked Questions

How many Kilometer are in 1 Fermi?

There are exactly 1.000000e-18 Kilometer in 1 Fermi. This means the conversion factor from Fermi to Kilometer is 1.000000e-18.

What is the formula to convert Fermi to Kilometer?

The formula to convert Fermi to Kilometer is: km = fm × 1.000000e-18. For example, to convert 10 Fermi to Kilometer, you would multiply 10 by 1.000000e-18.

What is a Fermi?