Free tool
Intermittent fasting planner
Choose a gentle eating window, see when it opens and closes, and print a 7-day plan or add reminders to your calendar.
Your 12:12 plan
Eating window: 8:00 AM–8:00 PM
Fasting window: 8:00 PM–8:00 AM (12 hours)
7-day schedule
| Day | Eating window | Fasting from |
|---|---|---|
| Monday | 8:00 AM–8:00 PM | 8:00 PM |
| Tuesday | 8:00 AM–8:00 PM | 8:00 PM |
| Wednesday | 8:00 AM–8:00 PM | 8:00 PM |
| Thursday | 8:00 AM–8:00 PM | 8:00 PM |
| Friday | 8:00 AM–8:00 PM | 8:00 PM |
| Saturday | 8:00 AM–8:00 PM | 8:00 PM |
| Sunday | 8:00 AM–8:00 PM | 8:00 PM |
Many people start with 12:12 and only lengthen the fast if it feels comfortable. Drink water; stop and speak to your doctor if you feel unwell, dizzy or faint.
Educational estimate, not medical advice. Talk to your doctor before making changes, especially if you have a health condition, take medication, or are pregnant.
How this works
You choose a pattern (for example 16:8 means a 16-hour fast and an 8-hour eating window) and the time of your usual first meal. The eating window runs from that time for the number of eating hours; the rest of the 24 hours is the fasting window. Windows can run past midnight.
The timer uses your device's clock and checks yesterday's, today's and tomorrow's windows, so it stays right across midnight and when weekend times differ. The calendar file is created in your browser with a daily reminder when your eating window opens.
What the evidence says: Studies, including randomized trials, have generally found time-restricted eating leads to weight loss similar to regular calorie reduction. Long-term effects are still being studied.
Limitations
- This is a planning aid, not advice on whether fasting is right for you.
- It doesn't consider medication, blood sugar or any health condition.
- The timer follows your device clock and time zone; travel or clock changes may shift it.
- 5:2 and other weekly patterns aren't timed here.
Privacy
Tool inputs stay on your device. Everything is calculated in your browser; nothing you enter is sent to us or stored, apart from optional preferences (such as units or your last schedule) saved in your own browser.
Frequently asked questions
What is intermittent fasting?
Intermittent fasting describes eating patterns that alternate eating periods with periods without food. It is about timing, not a required food list, and it is not suitable for everyone. Regular meals are also a valid approach. Discuss any proposed change with your doctor if your health or circumstances require extra caution.
What is intermittent fasting 16/8?
The label 16/8 describes a daily schedule with a sixteen-hour period without food and an eight-hour eating window. It is a description, not a recommendation or a promise. Whether any change in meal timing is appropriate depends on your circumstances; ask your doctor before trying it if there are health concerns.
Is intermittent fasting safe?
Intermittent fasting is not suitable for everyone, and a planner cannot establish whether it is safe for you. Pregnancy, breastfeeding, an eating disorder history and some health conditions or medications require particular caution. Talk with your doctor before changing meal timing; the tool is not permission to ignore medical guidance.
Is intermittent fasting safe during pregnancy?
Do not use an eating-window tool as guidance for fasting during pregnancy. Pregnancy changes nutritional needs, and meal timing should be discussed with your maternity care team. This website cannot assess your circumstances. Keep following your existing care advice rather than adopting a fasting schedule from a general calculator or article.
Is intermittent fasting safe while breastfeeding?
An online planner cannot tell you whether fasting is appropriate while breastfeeding. Your nutritional needs and circumstances deserve individualized discussion with your healthcare provider. Do not interpret a suggested schedule as medical clearance or change an established care plan because of it. Regular meals remain an option without using an eating window.
Sources
- Liu D et al. (2022). Calorie restriction with or without time-restricted eating in weight loss. N Engl J Med.
- Lowe DA et al. (2020). Effects of time-restricted eating on weight loss and other metabolic parameters: the TREAT randomized clinical trial. JAMA Intern Med.
- Trepanowski JF et al. (2017). Effect of alternate-day fasting on weight loss, weight maintenance, and cardioprotection among metabolically healthy obese adults. JAMA Intern Med.
- de Cabo R, Mattson MP (2019). Effects of intermittent fasting on health, aging, and disease. N Engl J Med.
- Mayo Clinic: Intermittent fasting: What are the benefits?
- National Institute on Aging: Research on intermittent fasting shows health benefits
Last reviewed by the Body Reset Guides editorial team