When does my fast end?
See the time remaining and an educational timeline. Hours on a clock are not a measurement of your body.
Your countdown
Not started0:00:00
- Remaining
- —
- Target time
- —
Pick when you last ate to start the countdown.
A time guide, not a body scan
These intervals follow the app’s educational guide. They count hours; they don’t measure glucose, ketosis, autophagy or fat burning, and no interval is a goal.
- 0–4 hAfter a meal
- 4–12 hBetween meals
- 12–24 hA longer interval
- 24–36 hExtended fasting: professional supervision
- 36+ hExtended fasting: professional supervision
The longer intervals explain the guide. They are not an invitation to keep fasting.
Questions about this tool
Is this a personal health recommendation?
No. These tools count time and share general education. They can’t tell whether fasting suits you, and longer is not better.
Which time zone does the calculator use?
Your device’s time zone. If the time you pick is later than now, it counts as yesterday. Hours are counted as elapsed time, so on a night when the clocks change the end time shifts by an hour.
Are my answers saved?
No. Everything runs in this browser; nothing is sent or stored. The countdown keeps its start time in the page address, so you can bookmark it. It doesn’t send notifications.