## Explanation

If you have an annual interest rate, and a starting balance you can calculate interest with:

```
=balance * rate
```

and the ending balance with:

```
=balance+(balance*rate)
```

So, for each period in the example, we use this formula copied down the table:

```
=C5+(C5*rate)
```

### With the FV function

The FV function can also be used to calculate future value. The equivalent formula is:

```
=FV(rate,1,0,-C5)
```

The interest **rate** is used as-is, since we are compounding annually, **nper** is 1, since there is only one period per year, **pmt** is zero, since there are no additional payments, and **pv** is the starting balance, input as a negative value by convention.