Jet Lag Recovery Calculator

Travelling east typically results in more severe jet lag because it forces your body to shorten its natural circadian rhythm, which is harder to adjust to than lengthening it. This is why flights heading west, where you 'gain' time, often result in milder symptoms. The calculator accounts for this by adjusting the estimated recovery days based on the direction of travel, with eastward flights generally requiring more recovery time.

The number of time zones crossed directly correlates with the disruption to your circadian rhythm. Each time zone represents an hour of difference that your internal clock needs to adjust to. Research suggests it takes about one day per time zone to fully recover, though this can vary based on individual factors like sleep patterns and travel direction. The calculator uses this principle to estimate recovery days, factoring in additional variables to refine the prediction.

Your usual bedtime helps determine how your circadian rhythm aligns with the local time at your destination. If your typical sleep schedule is significantly misaligned with the destination's time zone, the adjustment period will likely be longer. For example, a night owl travelling to a destination with an earlier local bedtime may find it harder to adjust. The calculator uses this input to provide a personalised recovery estimate based on your sleep habits.

The arrival local time impacts how soon you need to adjust to the destination's schedule. For instance, landing in the evening might align better with your natural inclination to sleep after a long flight, while landing in the morning may require you to stay awake longer to sync with local time. The calculator incorporates this factor to estimate how your sleep-wake cycle will need to shift, influencing the recovery days calculation.

Longer flights often lead to greater physical fatigue, dehydration, and disrupted sleep, which can exacerbate jet lag symptoms. Even if fewer time zones are crossed, the extended travel duration can strain your body, making it harder to recover. The calculator accounts for flight duration as a factor in the travel fatigue score, which indirectly affects the recovery estimate.

To optimise recovery, consider strategies like gradually adjusting your sleep schedule before departure, staying hydrated during the flight, and exposing yourself to natural light at your destination to reset your internal clock. Additionally, avoid heavy meals, caffeine, and alcohol close to bedtime. These steps can help reduce the number of recovery days needed, though the calculator provides a baseline estimate based on your trip details.

The 'Time Overlap Factor' measures how much your usual sleep schedule overlaps with the local time at your destination. A higher overlap indicates less disruption to your circadian rhythm, leading to a faster recovery. The calculator uses this factor to refine its estimate, providing a more personalised prediction of recovery days. For example, if your typical bedtime closely matches the destination's nighttime hours, your recovery may be quicker.

A common benchmark is the 'one day per time zone crossed' rule, but this is a generalisation and doesn't account for individual differences or travel details. Factors like flight direction, sleep patterns, and arrival time can significantly alter recovery times. The calculator builds on this benchmark by incorporating personalised inputs to provide a more accurate estimate tailored to your specific trip and habits.