When Should I Leave
for the Airport?
Stop guessing. Enter your flight details and get the exact time to leave your house. No stress, no showing up 7 hours early.
Calculate your departure time
Takes 30 seconds · Always free · All times are estimates
How Airport Math works
Airport Math works backward from your flight time and factors in the pieces people usually forget: drive time, parking or shuttle, checked bags, TSA PreCheck or CLEAR, and how early you like to board. You get one suggested time to leave home.
It is an estimate, not a guarantee, because traffic and security lines do what they want. When you are cutting it close, add a buffer.
Frequently asked questions
Is two hours early enough for a domestic flight?
Two hours is the common starting point for a domestic flight. Add time if you are checking bags, flying during a holiday rush, or leaving from a large airport, and the calculator adjusts for these. For the full breakdown, see our guide on how early to arrive at the airport.
Does the suggested time include driving and parking?
Yes. Airport Math gives you a leave-home time, not a get-to-the-terminal time. It includes your drive, plus parking or shuttle time when you add them.
How early should I arrive for an international flight?
Three hours is the usual recommendation for an international flight, mostly to cover document checks and earlier bag cutoffs. See our international flight guide for the details.
Does TSA PreCheck or CLEAR change the estimate?
Yes. Both can shorten your security wait, so the calculator trims the time it sets aside for the checkpoint when you select them. Not sure which is worth it? Our guide compares TSA PreCheck, CLEAR, and Global Entry.
Do I need an account or app?
No. Airport Math is free, needs no signup, and runs in your browser. Nothing you enter is stored.
What if my airport has long security lines?
Security waits vary a lot by airport and time of day. The estimate uses a reasonable planning figure, so when in doubt, add a buffer or check your airport’s current wait times before you leave.