Fasting window
The period you intend to avoid calorie intake. The tool shows elapsed time and progress toward the target.
Fasting Timer
Metabolic Health Assistant
Manage fasting and eating windows to improve metabolic health.
Eating Window
00:00:00
GOAL: 16 HOURS
A fasting timer tracks the window, not your health outcome
Intermittent fasting plans such as 16:8, 18:6, and 20:4 divide the day into fasting and eating windows. This timer lets you choose a 12, 16, 18, or 20-hour target, then shows elapsed time and progress so the window is easier to monitor.
Fasting-window concepts
Eating window
The period when meals may be planned. Food choices still depend on personal needs and context.
Target hours
Choose 12H, 16H, 18H, or 20H as the tracking goal for the current session.
How to use
- Select today's target fasting duration: 12H, 16H, 18H, or 20H.
- Press start fasting to track elapsed time and progress.
- End the fast when you reach your target or when you need to stop early.
Frequently asked questions
What does 16:8 mean?
It usually means a 16-hour fasting window and an 8-hour eating window, with start times adjusted to your schedule.
Does the timer recommend a diet?
No. It only tracks time. Nutrition, medical conditions, and meal planning should be discussed with a qualified professional when relevant.
What if I feel unwell during a fast?
If you feel dizzy, suspect low blood sugar, become dehydrated, or have concerning symptoms, stop and seek appropriate help.
Intermittent fasting is not appropriate for everyone; consult a medical professional first if pregnant, growing, ill, taking medication, or with a history of disordered eating.