Per Diem Calculator (2026)
Calculate GSA-style per diem: lodging per night plus meals & incidentals (M&IE) with the 75% first/last travel day rule and deductions for provided meals.
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The two pieces of per diem
Every per diem has the same anatomy:
- Lodging — a per-night allowance. Nights = trip days − 1 (a 5-day trip has 4 nights; a day trip has none).
- M&IE (meals & incidental expenses) — a per-day allowance covering breakfast, lunch, dinner, taxes, tips, and a $5 incidentals slice (porter tips, hotel staff — that $5 has been fixed since FY2022).
The official numbers come from the GSA per diem lookup (gsa.gov/travel), which publishes lodging + M&IE for every US locality each fiscal year. FY2026 runs October 2025–September 2026.
The 75% rule
Federal Travel Regulation §301-11.101: the first and last calendar days of travel are reimbursed at 75% of the M&IE rate. Full days in between get 100%. This is the single most-forgotten line in corporate travel budgets — a 5-day trip doesn't get 5 full M&IE days, it gets 2 × 75% + 3 × 100%.
Provided meals are deducted from that day's M&IE after proration: if your $79 M&IE day is a travel day ($59.25 at 75%) and the conference bought you lunch worth $23, you claim $36.25 for the day.
Worked example: 5-day trip, $150 lodging, $79 M&IE
| Day | Lodging | M&IE | Note |
|---|---|---|---|
| Day 1 (depart) | $150 | $79 × 75% = $59.25 | travel day |
| Day 2 | $150 | $79 | full day |
| Day 3 | $150 | $79 − $23 lunch = $56 | lunch provided |
| Day 4 | $150 | $79 | full day |
| Day 5 (return) | $0 | $79 × 75% = $59.25 | travel day, no night |
| Total | $600 | $332.50 | $932.50 |
Without the provided lunch it would be $955.50 — the same arithmetic the GSA's own examples use.
The private-sector shortcut: high-low rates
Looking up 295 localities is overkill for most companies, so the IRS publishes a high-low substantiation method each year. For the travel year beginning October 1, 2025: $319/day for high-cost localities, $225/day elsewhere in the continental US, with $86 / $74 treated as the meals portion. One policy line replaces the whole GSA book — at the cost of overpaying cheap destinations and underpaying expensive ones.
What this calculator assumes
- Lodging = (trip days − 1) × nightly rate; single-day trips get no lodging.
- M&IE proration defaults to the GSA 75% on first/last days; switch to 100% or a custom percentage if your company policy differs.
- Meal deductions use amounts you enter (from the GSA breakdown for your destination) — the calculator doesn't guess them.
- Incidentals ($5/day inside M&IE) are not separately itemized, matching GSA treatment.
Estimates only — not tax or financial advice. Verify current-year rates at the official GSA per diem lookup.
Data sources
- 75% rule: Federal Travel Regulation §301-11.101; GSA TDY Travel Policy OAS 5700.1D (Feb 2025), ch. 4.
- M&IE structure & $5 incidentals: GSA FY2026 per diem tables (e.g., DC: $92 M&IE = $23/$26/$38/$5; first/last day $69.00).
- High-low method: IRS Notice for the travel year beginning October 1, 2025 — $319 / $225, meals $86 / $74.
Frequently asked questions
What is per diem?
Per diem ('per day' in Latin) is a fixed daily allowance covering lodging, meals, and incidental expenses on business travel. Instead of saving every receipt, the traveler gets the allowance and keeps the difference if they spend less — which is exactly why employers cap it at published rates.
Why are the first and last travel days paid at 75%?
That's the federal rule (FTR §301-11.101): on departure and return days you typically don't need three full meals, so the meals & incidentals (M&IE) allowance is prorated to 75%. Lodging is unaffected — it's per night, and there are simply fewer nights than days.
How do provided meals reduce per diem?
When a conference or client provides a meal, you deduct that meal's value from the day's M&IE. The GSA publishes a breakfast/lunch/dinner breakdown for each locality (e.g., $23/$26/$38 inside a $92 M&IE rate for DC in FY2026). Enter those breakdown amounts in the calculator and check which meals were provided.
Do I have to use GSA rates for my company's travel?
No — GSA rates are mandatory only for federal travel. But the IRS lets private employers piggyback on them: reimbursements at or below the federal locality rate are 'deemed substantiated,' so nobody has to produce a receipt for every sandwich. That's why most corporate travel policies mirror GSA.
What is the IRS high-low method?
A simplified alternative to looking up 295 locality tables: for the travel year starting October 1, 2025 (FY2026), the IRS set $319/day for high-cost localities and $225/day everywhere else in CONUS, with $86 and $74 of those treated as the meals portion. Useful for employers who don't want locality-by-locality policies.
Are per diem payments taxable?
Generally no, if they're paid under an accountable plan at or below the federal rates and you report the time, place, and business purpose of the trip. Amounts above the federal rate, or paid without substantiation, can land on your W-2 as wages. This calculator doesn't give tax advice — check IRS Publication 463 or your plan documents.
Estimates only, not tax or financial advice. Figures reflect the 2026 tax year. Verify important decisions with the IRS or a qualified tax professional.