How TripStow measures on-time performance
Every flight, route and airport page on TripStow shows how often flights arrive on time. This page explains exactly what those numbers mean, so you can quote them with confidence.
What counts as on time
A flight is on time when it arrives within 15 minutes of its scheduled arrival. This is the definition the US Department of Transportation uses, and most airlines and airports use it too. Cancelled and diverted flights are counted separately, never as on time.
Where the figures come from
US Department of Transportation. For flights within the United States, we use the Bureau of Transportation Statistics on-time data, which records every domestic flight by a large US airline. It is public domain and published about two months after each month ends. Pages state the months they cover.
TripStow travellers. Travellers who forward their bookings build up real departure and arrival times. We publish these only as totals, only for flights at least a week in the past, and only once at least several different people have flown the same flight or route, so no figure can point back to anyone. Future trips are never public.
We never publish data from commercial flight-data providers, and we never show an individual booking.
Averages and rankings
- The on-time share is on-time arrivals divided by flights that actually operated.
- The average delay is the mean arrival delay across operated flights, so early arrivals count as negative minutes.
- Rankings in the monthly reports only include airlines with at least 1,000 flights, routes with 300 and flight numbers with 25 in the month, so a handful of flights cannot top a table.
Using our figures
You are welcome to quote TripStow figures with a link to the page they came from. Every flight, route and airport page also has an embeddable badge that stays up to date. Start at flight stats.