โ๏ธ Travel
Jet Lag Calculator
Jet lag severity depends on the number of time zones crossed and the direction of travel, because the body clock finds it easier to delay than to advance. Eastward travel is generally worse, and the rule of thumb is roughly one day of adjustment per time zone crossed.
How it works
Time zones crossed
Direction of travel
Flight duration
Sleep on the plane
Night flight
Traveller age
Expected severity
Days to fully adjust
Energy level on arrival day
Suggested plan
Note
Frequently asked questions
How do I use the Jet Lag Calculator?
Fill in the fields above โ the result recalculates instantly as you type. Everything runs in your browser, so the values you enter are never collected or stored.
Is this calculator free?
Yes. It is completely free, requires no account, and works on phones, tablets and desktops.