Formula help for bonus calculation with minimum threshold?

Hi All, I am trying to work out the best way to do enter a formula into a spreadsheet that calculates driver bonuses. My challenge for this is that the drivers have to do a minimum of 5 loads before they get anything then on the fifth they get a £15 bonus and then £15 per load thereafter (or part thereof). At first I thought:

=MAX(0,C21-4)*15 ..Where C21 is the input of the number of jobs done that day.

Of course that doesn't work because it would pay out on 4.25 loads or 4.5 loads...

Any help you could give me would be much appreciated! Thank you in advance.

Thank you for your very quick assistance on this. I have tried it and it works however how can I do it so that the minimum value is zero and not a negative value?

Originally Posted by Ace_XL

Try

=IF(C21<5,0,MAX(0,C21-4)*15)

That is it! Perfect! Thank you so much for your help.