A light year is a measure of distance that is used to refer to the length that light travels in a year, or in other words, a distance of 9,460,730,472,580.8 kilometers to be more exact. The number is huge and working with it can be tedious, which is why, our **light years to kilometers converter** will allow you to work with the transformation between both units.

Article sections

## How much is a light year

As we have said before, **one light year is equivalent to 9,460,730,472,580.8 kilometers.**. Therefore, the light year is a unit of length and not a unit of time as might be thought at first.

If you want the value of a **light year in scientific notation**equals 9.46 × 10^{12} km.

The name light year comes from the fact that it is the distance that light travels in a year. Recall that** the speed of light is equal to 3×10 ^{8} m/s **

### Why do we measure the distance of the universe in light years and not in kilometers?

This is basically a matter of distance.

**In the universe, distances are very large and the kilometer is very short.** to express lengths, therefore, the light year is a much more suitable unit for measuring the distance between planets, stars, satellites and other elements of space.

It is much more comfortable for us to say "1 light year" than "9,460,730,472,580.8 kilometers", and the same is true when performing operations. In addition, knowing the **equivalence between light years and kilometers** we can always go from one unit to another with a simple multiplication or division as we are going to see below.

## How to pass light years to km

For **from light years to kilometers** you will have to use the following mathematical formula:

9,460,730,472,580.8 x light years

For example, if we want to calculate how many are **40 light years in kilometers**The result looks like this:

9,460,730,472,580.8 x40 = 378,429,218,903,232 kilometers

If we do **in scientific notation**If we use a rounding method, we obtain a similar result, although with less precision due to rounding issues:

9,46 × 10

^{12}x 40 = 3,784 x 10^{14}

## Convert km to light years

If we want to **convert kilometers into light years**we will have to make the inverse operation, that is to say:

kilometers / 9,460,730,472,580.8

Or in scientific notation:

km / 9.46 × 10

^{12}

For example, how much is** 1 km in light years**? We apply the above formula and we get the following result:

1 km / 9.460.730.472.580,8 = 0,000000000000106 light years

As you can see, **the kilometer is a much smaller unit than the light year**.

## How to convert light years to kilometers in Excel

If at any time you do not have our **light years to km converter**You can create your own Excel converter in a matter of seconds.

Open a new spreadsheet and in an empty cell type the following function:

=CONVERT(C1; "ly"; "km")

You only have to replace the coordinates C1 with those of the cell in which you have written the **number of light years you want to convert into kilometers**. You can also write there directly the longitude in light years.

For example, if you want to know **how many is 20 light years in kilometers**the formula will be put like this:

=CONVERT(20; "ly"; "km")

In case you want to do the reverse conversion, ie, **from kilometers to light years in Excel**then you will have to use this other function:

=CONVERT(C1; "km"; "ly")

If you have any questions about **how to go from light years to km**Leave us a comment and we will help you.

Remember that if you want to **to any other unit** of the international system, you can use our distance unit converter.