Planning a work trip or checking an expense report? Pick where the work is and your travel dates, and this calculator adds up the federal per diem: the GSA lodging maximum for each night (it changes by month in many cities), the meals and incidental expenses (M&IE) rate at 75% on the first and last day, and the deduction for any meals you were given. It uses the official GSA rates for the continental US for federal fiscal years 2026 and 2027 (travel from October 1, 2025 to September 30, 2027), so it works for federal travelers, contractors and the many companies that reimburse at GSA rates. Everything runs in your browser and nothing is sent anywhere.

 

How the math works

lodging, each night   = actual hotel cost before taxes, up to the GSA maximum for that month
M&IE, full days       = GSA M&IE rate for the work location, for the fiscal year that day falls in
M&IE, first/last day  = 75% of the rate
meals provided        = minus the GSA breakdown amount for each meal, never below the incidentals amount
total per diem        = lodging + M&IE

Example with the default inputs: New York City, leaving Tuesday November 3, 2026 and home Friday November 6, 2026. In FY2027 the NYC lodging maximum for November is $358 and M&IE is $92, so lodging is 3 x $358 = $1,074, M&IE is $69 + $92 + $92 + $69 = $322, and the total per diem is $1,396. If lunch is provided at a conference on November 4, that day’s M&IE drops by $26 to $66.

The rules this follows

  • Lodging is a maximum, not an allowance. You get your actual hotel cost up to the GSA rate for that night, and the unused part can’t be moved to meals. Lodging taxes aren’t included in CONUS rates; federal travelers claim them separately (GSA per diem FAQ, FTR 301-11.16).
  • 75% on the first and last day. For trips of 24 hours or more, the day you leave and the day you return get 75% of the M&IE rate; full days get 100%. A one-day trip longer than 12 hours gets 75% (FTR 301-11.20).
  • Meals provided are deducted. When the government provides a meal or it’s included in a registration fee, you deduct the GSA breakdown amount for that meal. On the first and last day the full meal amount comes off the 75% rate, but you always keep the incidentals amount. Meals from an airline or a free hotel breakfast don’t count (FTR 301-11.21).
  • The work location sets the rate. The rate is based on where the work activities are, not where you sleep, unless the agency authorizes the rate where lodging is obtained. If a city isn’t listed, check its county; if neither is listed, the standard rate applies.
  • Fiscal years. GSA rates run October 1 to September 30, and each day uses its own fiscal year’s table, so a trip across October 1 can change rates mid-trip.
  • Continental US only. Alaska, Hawaii and US territories use Department of Defense rates, and foreign travel uses State Department rates, which aren’t included here.
  • Companies and contractors often reimburse at GSA rates, but the exact policy is theirs. If you’re self-employed and deducting meals, use the self-employed per diem meal deduction calculator, which follows IRS rules instead.

Sources: GSA per diem rates, GSA M&IE breakdowns, GSA per diem FAQ, and the Federal Travel Regulation, 41 CFR 301-11.20 and 301-11.21. Rates loaded from GSA’s per diem API and rules checked on October 20, 2026. This is general information; your agency’s or employer’s travel policy has the final word.

Tools from us

  • Per Diem Travel Expense Tracker (Excel + Google Sheets): log trips day by day at GSA FY2026 and FY2027 rates, with 75% first and last days, provided-meal deductions, lodging vs the GSA cap, and the 50% or 80% deductible meal amount from IRS Pub. 463. $9.
  • US Per Diem API: coming soon. GSA per diem rates by ZIP code or city for your own apps. Not available yet.

Disclosure: the Per Diem Travel Expense Tracker is our own paid product, and we earn the sale price if you buy it. Not affiliated with GSA or the IRS. Not tax advice.

Disclosure: the calculators on this site are our own. We don’t earn anything from the links in this list, and none are affiliate links. Not affiliated with GSA. More guides: Gumroad developer guides.