Intermittent Fasting Calculator

Set your eating window and fasting schedule in seconds.

Eating Window
Fasting Window
First meal (break fast)
Last meal (cut-off)
Fast begins again

What is intermittent fasting?

Intermittent fasting is an eating pattern that alternates between periods of eating and fasting. It does not specify which foods to eat but rather when to eat them.

Popular protocols

The 16:8 method is the most common: fast for 16 hours and eat within an 8-hour window. The 18:6 and 20:4 protocols are more restrictive and may be used for greater calorie control. The 12:12 method is a gentle starting point.

Who should be cautious

Intermittent fasting is not recommended for pregnant or breastfeeding individuals, people with a history of eating disorders, or those with certain medical conditions. Always check with a doctor first.

This calculator is for general informational purposes only. It is not a substitute for professional medical advice.