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⏰ Intermittent Fasting Calculator

Calculate your fasting start time, eating window, and autophagy timeline based on your wake time and chosen IF protocol.

If entered, fasting duration is calculated from this time

Popular IF Protocols

16:8: Most popular protocol. Fast 16 hours, eat in an 8-hour window. Often involves skipping breakfast.
18:6: More restrictive than 16:8. Suitable for those adapted to 16:8 wanting to increase fasting duration.
20:4 (Warrior): Very restrictive eating window of 4 hours. Not recommended for beginners.
OMAD: One Meal A Day — 23 hours of fasting. Only for experienced fasters; medical supervision recommended.
5:2: Normal eating 5 days; restrict calories to 500-600 kcal on 2 non-consecutive days per week.
Alternate Day: Alternate between normal eating days and fasting/very low calorie days.
'Does IF work for weight loss?', 'answer' => 'IF can aid weight loss primarily by reducing total caloric intake through a smaller eating window. Research shows it is roughly equivalent to continuous caloric restriction for weight loss. It may also improve insulin sensitivity and other metabolic markers.'], ['question' => 'Can I drink during the fasting window?', 'answer' => 'Water, black coffee (no milk or sugar), and plain tea are generally considered acceptable during the fasting window as they do not trigger an insulin response. Adding calories (milk, sugar, cream) would technically break the fast.'], ['question' => 'Who should not do intermittent fasting?', 'answer' => 'IF is not recommended for: pregnant or breastfeeding women, children and teenagers, people with type 1 diabetes (or type 2 on insulin), those with a history of eating disorders, and underweight individuals. Always consult your doctor before starting any fasting protocol.'], ]" />

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