Per Diem Total Calculator
A per diem is a fixed daily allowance that covers lodging, meals and incidental expenses during business travel, paid instead of reimbursing each receipt. This calculator finds the total by multiplying the number of travel days by the daily per diem rate. Enter the days you are traveling and the applicable daily rate, and the tool returns the total allowance. The US General Services Administration sets per diem rates for federal travel by destination, and the IRS lets employers use those rates without itemizing actual costs. The default uses a representative combined daily rate, but the rate input is editable so you can enter the exact GSA figure for your destination or your employer's amount. Seeing the total against the daily rate makes it easy to budget a trip or check a claim. Many travelers apply a reduced rate, often 75 percent, on the first and last travel days, which you can model by adjusting the days or rate. This tool computes the allowance only; taxability depends on whether it stays within the federal rate under an accountable plan. Every result here is computed deterministically from the formula shown in full below, with a worked example that reconciles exactly to the calculator so you can follow each step.
A per diem total is days times the daily rate: total = days times daily rate. For 5 travel days at a $178.00 daily rate, the total allowance is $890.00.
Per Diem Total formula
Total per diem = Travel days x Daily rate
Travel days = number of days on the trip
Daily rate = the per diem rate for the destination (set by the GSA for federal travel)
Some plans reduce the rate to 75% on the first and last travel days
Multiplying the days by the daily rate gives the full allowance; adjust the days or rate if your policy uses a reduced first-and-last-day amount.
Worked example
Find the per diem total for 5 travel days at a 178.00 daily rate.
- Multiply days by the rate: 5 x 178.00 = 890.00
- Total per diem = 890.00
- Daily rate applied = 178.00
These are the calculator's default inputs, so the result above matches the widget exactly.
Per Diem Total Calculator: frequently asked questions
What is a per diem?
A per diem is a fixed daily allowance an employer pays to cover lodging, meals and incidental expenses while traveling for work, instead of reimbursing each individual receipt. It simplifies expense reporting.
Where do per diem rates come from?
For federal travel, the US General Services Administration publishes per diem rates by city and county, with standard rates for locations not specifically listed. Many private employers adopt the GSA rates for consistency.
Is per diem taxable?
Per diem paid at or below the federal rate under an accountable plan, with proper expense substantiation, is generally not taxable to the employee. Amounts above the federal rate may be treated as taxable wages.
What about the first and last day of travel?
Many policies pay only 75% of the meals-and-incidentals rate on the first and last day of a trip. You can reflect this by adjusting the daily rate or the number of full-rate days in the calculator.
What is the per diem formula?
Total per diem equals travel days times the daily rate. For 5 days at 178.00, the total is 890.00.
Official sources
- US federal payroll, withholding and reimbursement guidance: US Internal Revenue Service (IRS). As at 25 June 2026.
Reviewed by the CalculatorHub team, edited by James Graham, 25 June 2026. See our methodology. This is general information, not financial, tax, legal or investment advice.