Create a payment code, with a Type of Rate, Payment/Deduction as Payment, Calculation Type as Hourly WTE, Factor as 1.00 (or 1.5 if doing overtime at 1.5).
Assign the payment code to the employee or category as required.
When you put hours against this code in payroll input, it will work out the rate as being:
Annual Salary (as shown in Salary History), multiplied by Factor, divided by Hours Per Week and Weeks Per Year (on employee terms record).
A code NORTH was set up with a factor of 1.5.
From an Annual Salary of £13250 – given an hourly rate of £10.19231.
Calculated as (13250 * 1.5) / (37.50 * 52.00).