Intermittent Fasting Calculator
Plan your eating and fasting windows for 16:8, 18:6 and other intermittent fasting schedules.
About the Intermittent Fasting Calculator
Time-restricted eating limits food to a daily window, such as 8 hours, and fasts for the rest. Studies find it helps some people eat less overall; its benefits for weight loss are similar to ordinary calorie reduction. Water, black coffee and plain tea are usually fine during the fast.
The formula
Fasting hours + eating hours = 24
Worked example
Example: Eating window = 10:30 – 18:30
- Inputs: Schedule: 16:8; First meal at: 10:30.
- Formula: Fasting hours + eating hours = 24
- Result: Eating window = 10:30 – 18:30
Things to keep in mind
- This is an estimate for general information, not medical advice. Talk to a doctor or other qualified professional about your health.
- Not recommended during pregnancy, for people with a history of eating disorders, or for those on diabetes medication without medical advice.
Questions people ask
Is 16:8 better than 14:10?
Not necessarily; choose the window you can keep up. Total food quality and calories matter most.
Does sleep count as fasting?
Yes, most of the fast happens overnight.