In 2026, calculating airline miles depends on whether your loyalty program is fare-based or distance-based. For "Big Three" U.S. carriers (Delta, United, American) and many Lufthansa Group airlines, you use a fare-based formula: (Base Fare + Surcharges) × Status Multiplier. For a standard member, the factor is typically 5, meaning a $500 base fare earns 2,500 miles. Conversely, for many international airlines like Air China or Singapore Airlines, miles are still calculated using the IATA physical distance between cities multiplied by a "Booking Class" percentage (e.g., 100% for Full Economy, 150% for Business). To get an exact figure in 2026, it is best to use the "Travel Calculator" found on the airline's website or app, as these tools now automatically account for "Qualifying Points" and "Segment Minimums." Remember that government-imposed taxes are always excluded from the "Base Fare" portion of the calculation.