Intermittent Fasting Calculator
Fasting and eating window schedule.
Enter your values
Results update instantly as you type — no submit needed.
Results
- Eating window
- 12:00 – 20:00
- Fast begins
- 20:00
- Fast ends
- 12:00
- Hours fasting
- 16
- Hours eating
- 8
- Fasting hours per week
- 112
Quick answer
Intermittent fasting sets a daily eating window; 16:8 means 16 hours fasting and an 8 hour window.
How to use the Intermittent Fasting Calculator
- 1Choose the hour of your first meal.
- 2Pick a fasting plan.
- 3Read your daily eating window.
Frequently asked questions
Does black coffee break a fast?
No — plain coffee, tea and water are fine.
Is 16:8 best?
It is the easiest to sustain; longer fasts offer diminishing returns for most people.