Grant Travel Budget (Per Diem) Calculator
Reviewed by Hamza Gujjar, Algorithm Architect & Software Developer
Last updated: July 27, 2026Grant Travel Budget (Per Diem) Calculator
Travel is a standard line item in most grant budgets - this calculator combines per diem rates, trip length, traveler count, and airfare into one clear total travel budget figure.
Formula
Total Per Diem = Travelers x Days x Per Diem Rate
Total Airfare = Travelers x Airfare Per Person
Total Travel Budget = Total Per Diem + Total Airfare
Example
3 travelers, 4 days, $79/day per diem, $450 airfare per person:
Per Diem = $948 → Airfare = $1,350 → Total Travel Budget = $2,298
Why Per Diem Rates, Not Receipts?
Many funders - particularly federal agencies - require travel costs to follow published per diem rate schedules rather than actual receipted meal and incidental expenses, simplifying both budgeting and expense reporting. Lodging is sometimes budgeted as a separate line item or included within a location-specific per diem rate, depending on the specific funder's travel policy, so always check whether your funder's per diem figure includes lodging before finalizing your travel budget.
Building an Accurate Estimate Upfront
Getting travel cost estimates right during proposal development avoids the need for later budget modification requests if actual travel costs (particularly airfare, which can fluctuate significantly) end up exceeding initial estimates once trips are actually booked.