Enter your last meal time and choose your fasting duration (e.g. 16:8, 18:6, 20:4) to calculate exactly when your eating window opens. You'll see your fast end time, total fasting hours, and a breakdown of your fasting vs. eating window — perfect for planning any intermittent fasting method.
Eat Again At
--
Fasting Duration
--
Eating Window
--
Fast Ends At
--
The 16:8 method involves fasting for 16 consecutive hours and restricting all eating to an 8-hour window each day. For example, if your last meal is at 8 PM, your next meal would be at noon the following day. It's the most popular form of intermittent fasting due to its flexibility.
Intermittent fasting reduces the overall window in which you eat, which naturally limits calorie intake for many people. It also lowers insulin levels and encourages the body to burn stored fat for energy during the fasting period. Research suggests it can be as effective as traditional calorie restriction for fat loss.
The 5:2 diet involves eating normally for five days a week and significantly reducing calorie intake (typically to 500–650 calories) on two non-consecutive fasting days. Unlike daily time-restricted eating, the 5:2 method focuses on weekly calorie cycling rather than daily fasting windows.
Several studies suggest intermittent fasting can improve markers of metabolic health, including lower fasting insulin, reduced blood sugar levels, and improved cholesterol profiles. These effects are most pronounced when IF is combined with a balanced, nutrient-dense diet.
Alternate-day fasting involves alternating between regular eating days and fasting days, where you either eat nothing or restrict intake to about 25% of your normal calories. It's a more aggressive approach than 16:8 or 5:2, and may not be suitable for everyone.
Staying well-hydrated with water, black coffee, or plain tea can significantly reduce hunger signals during a fast. Eating high-protein and high-fiber meals during your eating window also helps you feel fuller for longer. Hunger during fasting typically peaks and then subsides, especially after the first few days of consistent practice.
Yes — water, black coffee, plain tea, and sparkling water are generally considered safe during a fast and won't break it. Avoid drinks with calories, sugar, or milk, as these can trigger an insulin response and interrupt the fasting state.
Common pitfalls include overeating during the eating window, consuming calorie-containing drinks during the fast, choosing inconsistent fasting windows, and not eating enough nutrients when meals do occur. Starting with a shorter fast like 12:12 and gradually extending it can help build sustainable habits.