Intermittent Fasting Calculator

How It Works

Intermittent fasting (IF) is an eating pattern that cycles between periods of fasting and eating. The most popular protocol is 16:8, where you fast for 16 hours and eat within an 8-hour window. Research shows IF can improve insulin sensitivity, support fat loss, and simplify meal planning. The 18:6 and 20:4 protocols compress the eating window further, which naturally limits calorie intake. OMAD (One Meal A Day) is the most extreme daily protocol, requiring careful planning to hit protein and nutrient targets in a single meal. The 5:2 method takes a different approach — you eat normally five days a week and restrict to about 500 calories on two non-consecutive days. IF works primarily through calorie restriction, not through any metabolic magic. The best protocol is the one you can sustain consistently while meeting your nutritional needs.