Jet Lag Calculator
Jet lag hits when your body clock is still on home time but the clock on the wall says otherwise. Your body adjusts about 1 hour a day after flying east and about 1.5 hours a day after flying west, and shifting your sleep for a few days before you fly gives you a head start.
How long will my jet lag last?
Pick the time difference at your destination and enter your usual sleep times.
Adjusting on arrival only
6 days
With the plan below
3 days
Before you fly: go to bed and get up 1 hour earlier each day
| Day | Bedtime | Wake up |
|---|---|---|
| 3 days before | 10:00 PM | 6:00 AM |
| 2 days before | 9:00 PM | 5:00 AM |
| 1 day before | 8:00 PM | 4:00 AM |
On arrival
You're flying east, so your body will want to stay up late. Get outside in the morning daylight, avoid bright screens in the evening, and go to bed at the local bedtime even if you're not tired yet.
Recovery times are rules of thumb for healthy adults; how fast you adjust varies with age, sleep before the flight and light exposure.
Flying east vs. flying west
Flying east (say, New York to Paris) moves the clock forward, so you have to fall asleep and wake up earlier than your body expects. That is the harder direction: most people adapt by only about 1 hour a day. Flying west (Paris to New York) gives you a longer day, and staying up later comes more naturally, so you adapt by about 1.5 hours a day.
How to get over jet lag faster
- Shift your sleep 1 hour a day for a few days before departure, using the plan above.
- Switch your watch and phone to destination time when you board, and eat meals at local times.
- Light is the strongest signal to your body clock: time your daylight exposure for your direction of travel.
- Drink water, and go easy on alcohol and caffeine, both of which make sleep at the new time harder.
- If you must nap on arrival day, keep it short with the nap calculator, then plan your first night with the sleep calculator.
More free sleep tools
Sleep Calculator
Best bedtime or wake-up time based on 90-minute sleep cycles.
Nap Calculator
When to set your alarm for a power nap or a full-cycle nap.
Sleep Debt Calculator
How much sleep you owe from the past week, and how to pay it back.
REM Sleep Calculator
When each REM period happens and how much REM sleep you get.
Sleep Efficiency Calculator
What share of your time in bed you actually spend asleep.
Frequently asked questions
How long does jet lag last?
As a rule of thumb, your body clock shifts about 1 hour a day after flying east and about 1.5 hours a day after flying west. Crossing 6 time zones eastward can mean around 6 days before you feel fully in sync, and about 4 days going west.
Why is flying east worse than flying west?
Your natural body clock runs slightly longer than 24 hours, so it is easier to stay up later (flying west) than to fall asleep earlier (flying east). Flying east asks you to sleep when your body still thinks it's evening at home.
Should I sleep on the plane?
Sleep if it is night at your destination, and try to stay awake if it is daytime there. An eye mask and earplugs help; if you must stay awake on arrival day, a short nap of 20 minutes or less won't derail your adjustment.
Does melatonin help with jet lag?
Studies suggest a low dose of melatonin taken at the local bedtime can help, especially after flying east. Check with a doctor or pharmacist first, particularly if you take other medication.