Per Diem Calculator
Your trip
Per diem total
How to use the per diem calculator
- Enter trip days — calendar days away, not nights.
- Look up your destination's rates — GSA standard is \$110 lodging / \$68 M&IE; high-cost cities run to \$180+/\$92. gsa.gov/perdiem has every county.
- Keep the 75% travel-day rule — first and last days pay 75% of M&IE under GSA method.
- Read the total — what the trip reimburses tax-free at government rates.
Per diem: flat-rate travel money, done by the book
Per diem replaces receipt-chasing with flat daily rates: lodging per night plus M&IE (meals and incidentals) per day. A 4-day trip at the GSA standard ($110/$68) reimburses $330 lodging + $238 M&IE = $568 - with travel days automatically at 75% of M&IE, the detail every manual calculation gets wrong. Reimbursement at or below GSA rates stays tax-free to the employee and deductible to the company.
The rules that trip people up
A 4-day trip has 3 lodging nights. First and last days pay 75% of M&IE regardless of departure time. Lodging above the GSA cap requires either receipts-based reimbursement or the excess taxed as wages. Self-employed travelers can use M&IE per diem but must deduct actual lodging with receipts - the lodging per diem is employees-only.
Employer or employee - why per diem wins
No receipt archaeology, predictable trip budgets, no "is a minibar water incidental" arbitration. Employees keep what they don't spend; companies cap exposure. The only real decision is the rate table: GSA rates for defensibility, or company rates at/below them.
Day trips break the per diem model entirely
No overnight stay means no lodging night, and the IRS treats meal reimbursement as taxable wages unless the trip requires rest away from home overnight - the "sleep or rest" test. A round trip that leaves at 6am and returns at 9pm books zero lodging nights, so reimbursing it as tax-free per diem is wrong: it's a taxable meal allowance that belongs on a paycheck, not an expense report. This calculator's nights-equal-days-minus-one math already reflects that split; a 1-day entry returns 0 lodging nights by design, not a rounding artifact.
Deduct the meal that's actually provided, not a share of the day
When a conference or client covers one meal, GSA's M&IE isn't one number you can split into thirds. It's four line items - breakfast, lunch, dinner, incidentals - that sum to the daily total, each with its own published rate. Subtracting "1/3 of M&IE" for a provided lunch either overpays or underpays versus pulling the actual lunch line from the GSA meal breakdown table. Get it wrong at scale and the shortfall either shorts the traveler or creates a taxable-wage gap between what was reimbursed and what the accountable plan actually allows.
High-low method vs city-by-city lookup
Instead of pulling a per diem rate for every destination county, the IRS also permits its high-low substantiation method: one flat rate for designated high-cost localities, a second flat rate for everywhere else in CONUS, each split into its own lodging and M&IE pieces. It trades precision for consistency - useful when crews rotate through a mix of cities and nobody wants to look up a new county rate every week. The catch: once an employer applies high-low to a given employee, it has to stay high-low for that employee for the rest of the calendar year. Mixing methods mid-year for the same traveler isn't allowed, even if a later trip lands in a city with a published GSA rate that would pay out differently.
Weekend layovers still draw full per diem
A Saturday-night stay bought to cut airfare isn't a first or last travel day just because it falls outside the workweek - the 75% haircut only applies to the actual departure and return dates. A Monday-to-Friday-plus-Saturday trip pays 75% M&IE on Monday and Saturday (or Monday and the actual last day, if travel ends Sunday), full M&IE on Tuesday through Friday, and full lodging every night in between, weekend included. Skipping the extra hotel night to "save" the company money often costs more once you compare it against a same-day last-minute fare, which is the actual math worth running before cutting a trip short.
Related tools
Field crews traveling to jobs? Roll per diem into quotes with the job costing calculator. Self-employed: the M&IE deduction flows into your 1099 tax estimate. Reimburse mileage too - it stacks with per diem.
Standards and references
Per-diem amounts default to the GSA (US General Services Administration) FY 2026 CONUS per-diem rate schedule. The 75% first-and-last-day rule this calculator applies is defined in Federal Travel Regulation (FTR) Section 301-11.101. International (OCONUS) per-diem rates come from the US Department of State Foreign Per Diem Rates; DoD-controlled locations from the DoD Per Diem Committee.
Frequently Asked Questions
What is the standard per diem rate?
The GSA standard for FY2026 is about $110/night lodging and $68/day M&IE; high-cost cities run substantially higher. Look up your destination at gsa.gov/perdiem.
Why do first and last days pay 75%?
GSA's travel-day rule — partial days on the road get 75% of M&IE regardless of what time you left. Both this calculator and federal travel systems apply it automatically.
Is per diem taxable?
Not when paid at or below GSA rates under an accountable plan. Amounts above the federal rate are taxable wages unless backed by receipts.
Can self-employed people use per diem?
For meals (M&IE) yes; lodging must be actual expenses with receipts. The M&IE deduction is then subject to the 50% meals limitation.