Intermittent Fasting Timer & Tracker
Start a fast with one tap and see exactly how long you have been fasting, when your eating window opens, and your recent history. Your fasts are saved on this device.
This fast
Recent fasts
| Started | Length | Goal |
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Saved only in this browser. You can edit the start time if you forgot to start the timer.
How to use the fasting timer
- Pick a plan: 16:8 means 16 hours fasting and an 8-hour eating window.
- Tap Start fast when you finish eating. If you forgot, start it and adjust the start time.
- Tap End fast when you eat again; the fast is added to your history.
Popular intermittent fasting schedules
Time-restricted eating limits food to a daily window. 16:8 (for example, eating between noon and 8 p.m.) is the most common starting point; 14:10 is gentler, and 18:6, 20:4 and one meal a day (OMAD) are more demanding. Water, black coffee and plain tea are generally allowed during the fast.
Research suggests intermittent fasting can help some people eat fewer calories and lose weight, with results broadly similar to other calorie-reduction approaches. The best schedule is one you can keep consistently.
Fasting is not appropriate for everyone, including people who are pregnant or breastfeeding, have diabetes or take glucose-lowering medication, have a history of eating disorders, or are under 18. This calculator gives general estimates for information only and is not medical advice. Talk to your doctor before starting.
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Frequently asked questions
What does 16:8 mean?
Sixteen hours of fasting followed by an eight-hour eating window, repeated daily.
Can I drink coffee while fasting?
Black coffee, plain tea and water are commonly allowed; added sugar or milk breaks a strict fast.
Does the timer keep running if I close the page?
Yes. The start time is saved in this browser, so the timer picks up where it left off.
Is intermittent fasting safe?
For many healthy adults, yes, but it is not suitable for everyone. Check with your doctor first.