Federal Per Diem Calculator

How per diem is calculated

A federal per diem is two separate allowances added together, and each one is calculated differently.

Lodging is a nightly ceiling. You are reimbursed what you actually paid, up to the maximum for that destination and that month. A $92 room in a $113 location reimburses $92, not $113. Hotel taxes on lodging are reimbursed on top and do not count against the ceiling.

Meals and incidentals (M&IE) is a flat daily amount that does not need receipts. Under the Federal Travel Regulation you receive the full tier amount for each full day away, and 75% of it on the day you leave and the day you return.

Two rules decide which figures apply. The federal fiscal year runs 1 October to 30 September, so a trip crossing 1 October is priced under two rate sets, night by night. And the lodging maximum follows the month each night falls in, not the month you booked or filed.

Rates come from the GSA Per Diem API.

First and last day 75% rule

On the first and last day of travel you get 75% of the destination’s full M&IE, whatever time you actually left or got back. There is no half-day arithmetic and no departure-time threshold: a 6am start and a 9pm start both earn the same three-quarter day.

GSA publishes the reduced figure directly in the data as the first/last day amount, so the five gsa per diem meals tiers each have a fixed travel-day value.

The practical effect is that a trip always earns one fewer full M&IE day than you might expect. Three nights away means four travel days: two at 75% and two at 100%. On the $92 tier that is $69 + $92 + $92 + $69 = $322, not $368.

A same-day trip with no overnight stay is all first-and-last day: 75% of M&IE and no lodging at all, assuming your agency authorises meal reimbursement for travel without an overnight. Where a destination has different rates than the standard, the tier follows the destination, not your home office.

Seasonal lodging rates

Lodging maximums are set month by month, and in the FY2027 data 151 of the 297 listed destinations change rate during the year. The other 146 hold one figure for all twelve months. Move the same meeting by a few weeks and the ceiling can move by a hundred dollars a night.

Five destinations people look up often, with their FY2027 range:

DC is the clearest case: $295 in the spring conference season, $192 in July and August when Congress is out. Miami runs the opposite way, peaking in winter and bottoming out through the summer.

The seasons apply per night, so a stay that straddles a boundary is priced in two parts. A Seattle trip from 29 October to 2 November 2026 gets $255 for the October nights and $188 from 1 November. The calculator above splits this automatically; the rates lookup shows all twelve months for one destination.

Worked example: 3 nights in Denver

Take a trip to Denver, departing Monday 5 October 2026 and returning Thursday 8 October 2026: three nights, four travel days, all inside FY2027.

Denver / Aurora, CO is a listed destination. Its FY2027 lodging rate is $170 from November through March and $227 from April through October, and it sits in the top $92 M&IE tier. All three nights fall in October, so all three are priced at $227.

There is no lodging on the return day because you do not stay that night. The two $69 figures are the 75% rule on the $92 tier.

The same trip in February 2027 would be $170 a night, a trip maximum of $832. If it ran 30 September to 3 October 2026 instead, the first night would be priced under FY2026 at $215 and the rest under FY2027 at $227.

$1,003 is a ceiling, not a payment. If the hotel bills $180 a night you claim $540 of lodging, plus taxes, plus the full $322 of M&IE.

What’s not covered (taxes, mileage)

Per diem covers lodging, meals and incidentals. Several common travel costs sit outside it entirely and are claimed as separate line items on the voucher.

• Lodging taxes. In CONUS these are reimbursed as a miscellaneous expense on top of the nightly ceiling, so a $113 room with $16 of tax does not breach the cap.
• Mileage for a privately owned vehicle. Paid at the separate GSA POV mileage rate per mile driven, not out of M&IE.
• Airfare, rail, rental cars, parking, tolls and baggage fees. Transportation expenses, claimed at actual cost under your agency’s policy.
• Conference and registration fees. Separate, though a registration fee that includes meals usually triggers a provided-meal deduction from that day’s M&IE.

Two things reduce what you can claim rather than add to it. If a meal is provided (by a conference, a host or a flight), your agency deducts that meal’s amount from the day’s M&IE; only the $5 incidental portion always stays. And if your lodging is government-furnished or you stay with family, there is no lodging claim.

This site covers CONUS only. OCONUS and foreign rates are set by the Department of Defense and the Department of State, not GSA, and are not in this calculator. Check your agency’s own travel policy before filing: GSA sets the maximums, your agency decides what it reimburses. See GSA per diem rates.

Frequently asked questions