Calculate Number of Work, Annual Leave and Sick Hours from Budgeted Hours

[psycoperl]

I am trying to figure out how to determine the number of Work, Annual and Sick hours an employee would be assigned based on their allocated budget.

Once an employee works 500 hours they are entitled to one hour of annual leave per every 15 hours worked and 1 hour of sick leave for every 20 hours worked. Leave hours are only issued as full hours.

So for Budget Hours 0 - 499 the hours breakdown is easy as budget hours = work hours; but the issue is how can I determine from the hours budgeted the number of hours available for each leave.

For example:

Budget Hours	Work Hours	Annual Hours (rate 1 for every 15 work; whole hours only)	Sick Hours (rate 1 for every 20 work; whole hours only)	Annual/Budget	Sick/Budget
1161	1040	62	52	0.053402	0.044789
580.5	519.5	35	26	0.060241	0.044750
581	520	35	26	0.060293	0.044789

I had thought that I could use a percentage for each one, but when comparing each value the percentages are not exactly the same for each.

I just have no clue where to begin with this so suggestions and guidance would be appreciated.