How to Use the Intermittent Fasting Timer
Intermittent fasting (IF) restricts eating to specific time windows rather than limiting which foods you eat. This calculator shows you your exact eating window and fast start time based on your chosen protocol and the time you plan to break your fast.
Fasting Patterns Explained
16:8: The most popular protocol. Fast for 16 hours, eat within 8. Since sleep covers 7–8 hours of the fast, you're only skipping food for 8–9 waking hours. Easiest for beginners.
18:6: A step up from 16:8 with a 6-hour eating window. Common eating windows are 12 PM–6 PM or 1 PM–7 PM.
20:4: A 4-hour window requires careful planning to fit sufficient nutrition into a narrow timeframe. Popular among experienced IF practitioners.
OMAD (One Meal a Day): A single 1-hour eating window per day. Requires a nutrient-dense meal. Not recommended without prior IF experience.
FAQ
IF works primarily by reducing total calorie intake over time. The eating window naturally limits opportunities to eat. Research shows it is as effective as traditional calorie restriction for most people, with the added benefit of simplicity.
Yes. Fasted cardio is popular and may enhance fat burning. For strength training, eating protein within 2 hours post-workout is beneficial for muscle recovery — consider timing workouts just before your eating window.
Black coffee contains essentially zero calories and does not break a fast for most purposes. Lattes, cappuccinos, and any coffee with milk, cream, or sugar contain enough calories to end the fasted state.