UltimateTools
Travel & Transport

How to Use the Jet Lag Calculator

Enter your departure and destination time zones, flight timing, and typical sleep schedule — the calculator generates a personalized adjustment plan, including recommended light exposure and sleep timing before, during, and after the flight, based on the travel direction and time difference.

The Jet Lag Calculator builds a personalized plan based on the specific trip's direction and time difference — here's what to enter.

Entering trip and schedule details

Enter departure and destination time zones, flight dates and times, and your typical sleep schedule — the calculator uses these to determine the specific direction and magnitude of adjustment needed, as covered in the eastward-vs-westward guide.

Following the generated light and sleep timing plan

The resulting plan typically recommends specific light exposure and sleep timing for the days before, during, and after the flight — following it as closely as practical, as covered in the adjustment-mechanism guide, gives the best chance of a faster, less severe adjustment.

Frequently asked questions

What if I can't follow the full pre-flight plan due to my schedule?

As covered in the pre-flight-vs-post-arrival guide, even a partial pre-flight adjustment provides some benefit — following as much of the plan as practical, and focusing more heavily on light exposure management after arrival, still helps even without a complete pre-flight routine.

Does the calculator account for which direction I'm traveling?

Yes — since eastward and westward travel require different adjustment strategies (as covered in the eastward-harder guide), the calculator generates a plan specific to the actual direction and time difference of the entered trip.