How we get the rates

• CONUS lodging and M&IE: GSA per diem master files for FY2027, FY2026, FY2025, from gsa.gov.
• Every FY2027 rate was checked against GSA's ZIP code file: all 40,426 ZIP codes × 12 months match.
• M&IE breakdown: GSA Per Diem API.
• Mileage: IRS standard mileage rates page and GSA POV mileage page.
• Calculator rules: Federal Travel Regulation, 41 CFR 301-11 (75% M&IE on the first and last day).

Last data build: November 10, 2026.