# Calculating Log Returns in Excel

### What is a log return?

It’s simply a change in price expressed as percentage. You often hear S&P 500 is up today by 0.5%. A log return of S&P 500 for today would be 0.5%.

### How to calculate log returns in Excel?

First you’ll need some data, you can get it for free on Yahoo! Finance website. Here in our example we’ll use BTC/USD, you can download it here.

When you download the file, it will be a CSV file which you can open with Excel like any other CSV file. It will look like this:

Now, that you have the data ready, we start calculating log returns. In calculating returns we always skip the first data point, because we need to calculate *the difference* between current day and previous day.

The formula in Excel for calculating our fist log return in our example is:

```
=ln(f3/f2)
```

Pasting that formula will give you similar result like the this screenshot:

Now, we just apply this formula for all the following cells in the H column, and we apply some formatting to get it to look like this:

We now have our log returns ready, but what can we do with them?

Check these tutorials to continue: