I have an Excel spreadsheet which includes a calculation of annual mileage
which I then need to convert into a cost.

However, the rate of mileage depends on the amount of mileage, i.e. the
first 10,000 miles at 40p, and mileage in excess of that at 25p.

Currently I have =E9*0.40, however I need to have something in the formula
that ensures that any mileage in excess of 10,000 is calculated at the
reduced rate of 0.25.

Is there a way of doing this? Thanks!