Intermittent fasting window planner

Enter the time you want to start eating and your target fasting duration (16:8, 18:6, 20:4...) to instantly get the exact times of your eating window and fasting window. Everything is calculated right in your browser.

Example:
The time you have your first meal of the day
For example 16 for a 16:8 protocol
Common protocols:

How it works

Intermittent fasting alternates an eating window (during which you can eat) with a fasting window (during which you abstain from any caloric intake). This tool starts from the time of your first meal and the fasting duration you choose to automatically calculate the end of the eating window, as well as the start and end of the fasting window, over a 24-hour cycle.

Which protocol should I choose (16:8, 18:6, 20:4...)?

The larger number is the length of the fast, the second is the length of the eating window. 16:8 (16 hours of fasting, 8 hours to eat) is the most common protocol and the easiest to stick to day to day. Stricter protocols such as 20:4 or OMAD (one meal a day) shrink the eating window further and mainly suit people who are already used to fasting.

Does this tool replace medical advice?

No. This planner is for information only: it calculates times without taking your health into account. Intermittent fasting isn't suitable for everyone (diabetes, pregnancy, eating disorders, certain medications...). Always ask a healthcare professional for advice before making lasting changes to your eating habits.

The calculation happens entirely in your browser: no data you enter is sent to a server.