Per Diem Travel Reimbursement Calculator
Estimate your total per diem reimbursement for a business trip based on travel dates, lodging, meals & incidentals, and optional taxes or extra expenses.
What is per diem?
Per diem is a daily allowance paid to travelers for work-related trips. It usually covers meals, incidental expenses, and in many policies, lodging. Instead of submitting every small receipt, employees and contractors can use approved daily rates to simplify reimbursement.
In the U.S., many organizations reference federal benchmarks such as GSA rates for the continental U.S., while others use internal company tables. The exact method can vary by employer, contract type, and agency rules.
How this calculator works
This tool estimates reimbursement with a standard structure:
- Travel days: counted inclusively from start date to end date.
- Lodging nights: one less than travel days for overnight trips.
- M&IE: first and last day at a reduced percentage, full rate for middle days.
- Optional additions: lodging tax and other reimbursable costs.
Formula summary
- If trip is 1 day: M&IE = full-day rate × first/last-day %
- If trip is 2+ days: M&IE = (2 travel days × reduced %) + (middle days × full rate)
- Lodging = nightly rate × number of nights
- Total = M&IE + lodging + lodging tax + extra reimbursable expenses
Example calculation
Suppose your trip runs Monday through Thursday (4 days, 3 nights), with a full M&IE rate of $79 and a lodging rate of $165:
- First and last day M&IE at 75%: 2 × ($79 × 0.75) = $118.50
- Middle days M&IE: 2 × $79 = $158.00
- Total M&IE: $276.50
- Lodging: 3 × $165 = $495.00
- Estimated reimbursement before extras/tax: $771.50
Important policy details to confirm
Before you submit reimbursement, verify your specific policy for:
- Whether lodging is reimbursed by per diem table or actual receipt amount.
- How same-day travel is handled.
- Whether first/last-day reduction is 75%, 50%, or another value.
- Whether conference-provided meals require deduction from M&IE.
- Receipt requirements for parking, tolls, rideshare, and baggage fees.
Tips for accurate travel reimbursement
1) Use destination-specific rates
Per diem can differ significantly by city and season. If your employer follows federal tables, use the location and month of travel to get the correct rate.
2) Keep a simple travel log
Track departure time, arrival time, and overnight stays. Good records help avoid payroll delays.
3) Separate per diem from mileage
Per diem covers daily subsistence costs, while mileage reimbursement is typically calculated separately using a per-mile rate.
Frequently asked questions
Is per diem taxable income?
It may be non-taxable when paid under an accountable plan and within policy limits. Amounts above allowed limits or paid without proper substantiation can become taxable. Consult your tax advisor for guidance.
Can I claim full M&IE on travel days?
Many policies reduce first and last day allowances. A common standard is 75%, but your organization may differ.
Does this calculator replace official reimbursement rules?
No. This is an estimate tool for planning and quick checks. Your employer, agency, or contract terms always control final reimbursement.