How this number is made
A per diem is a daily amount for meals or incidentals. This page multiplies the rate by the days and subtracts what you expect to spend. Whether the allowance is taxable depends on whether it is within an accountable plan. This page does not decide that.
- Use the rate your employer or the GSA city rate actually pays.
- Days should follow the travel rules you are under. First and last days are often partial.
Formula
Allowance = rate × days. Left = allowance − spending.
Worked example
With the figures already in the form, left after spending is $92.00.
Questions
Is a GSA rate required here?
No. Type the rate you were given. Federal travelers look up a city rate. A private employer can set its own.
Is the leftover income?
Under many accountable plans, a per diem within the allowed rate is not extra wages. Spending less does not automatically create taxable income. The plan’s rules control.