Per Diem Calculator
Calculate per diem reimbursement from lodging, M&IE, full days, and partial travel days.
Written by Golam Rabbani, Founder & Lead Engineer
How to use this per diem calculator
- Enter the number of full days at the destination and any partial (travel) days.
- Set the partial-day M&IE rate — 75% is the US GSA convention for departure/return days.
- Enter your lodging rate per night and your M&IE (meals & incidentals) rate per day.
- Press Calculate to see lodging total, M&IE total, and the combined per diem reimbursement.
- Copy the breakdown for an expense report or travel summary.
About this per diem calculator
The per diem calculator turns travel dates and government-style rates into a single reimbursement figure. It splits the math the way most policies (including US GSA) do: lodging is paid only for full nights at the destination, while M&IE is paid at full rate for full days and at a reduced rate (typically 75%) for travel days at the start and end of the trip.
Worked example: a 5-day trip with 3 full days and 2 travel days, lodging rate $150/night, M&IE rate $74/day, travel-day rate 75%. Lodging = $150 × 3 = $450. M&IE = $74 × (3 + 2 × 0.75) = $74 × 4.5 = $333. Total per diem = $450 + $333 = $783.
Per diem rates vary by destination and year — look up the official rate for your country, state, or county before entering values. The tool does no rate lookup; you supply the numbers and it does the arithmetic.
FAQ
- What is M&IE?
- Meals & Incidental Expenses — the per-day allowance that covers food and small expenses like tips and short taxi rides. In US federal travel it is a single daily figure separate from lodging.
- Why is the travel-day rate 75%?
- The US GSA standard reduces M&IE on travel days to reflect the fact that you are usually only at the destination for part of a meal cycle. 75% is the long-standing default, but your policy may use a different value — change it in the field if so.
- Does lodging apply to travel days?
- In this calculator lodging applies to full days only, matching the most common interpretation: you pay for nights actually spent at the destination. If your policy pays lodging on the departure night but not the return night, count it as a full day in the calculator.
- Where do I get accurate per diem rates?
- For US federal travel, the GSA publishes rates by city and fiscal year. For other countries, check the relevant government travel authority. Most companies publish their own table — use that if you are filing an internal expense report.
- Does it save my trip data?
- No. Everything runs locally in your browser. Inputs are never sent to a server or stored.