need formula to calculate total salary

[Janelle Archilta]

I need a formula that will calculate a persons total salary: beginning of the year he is paid 10.50, but after an annual review he is given a 5% increase therefore making 11.03, but my formula needs to be a total of both rates, lets say his increase is in may....please help, i have tried it a couple of ways, but would like it to take up less rows.

 

[Luke M]

Assumptions:
Base rate is in A2
Percent raise is in B2
Date of raise is in C2
Raise takes effect first day of month given in C2
2000 work hours per year

Formula then is:
=A2*2000/12*(MONTH(C2)-1)+A2*(1+B2)*2000/12*(12-MONTH(C2)+1)