Free tools
Free intermittent fasting tools
Work out when you can eat, your stage, your water and protein, and print your fasting week, right in your browser
Free calculators and printables for intermittent fasting. They all run in your browser, so nothing you enter is sent anywhere.
- Intermittent fasting calculatorEnter when you last ate and your plan, and see when you can eat again, when your eating window closes and the stages on the way
- What fasting stage am I in?Enter when you last ate to see how long you've fasted, the stage your body may be in and when the next one begins
- How much water should I drink?A daily amount to drink from the official reference values, with extra for exercise and hot days
- How much protein do I need?Grams a day from your body weight, and how much to put on each plate in your eating window
- BMI calculatorYour body mass index, its category and the healthy weight range for your height
- When will I reach my goal weight?Enter your weight and your goal to see when you could get there at a steady, sustainable pace
- Printable intermittent fasting scheduleChoose your plan and when you stop eating, then print a week of fasts to stick on the fridge
- Fasting stages chartThe eight stages your body may move through, from your last meal to 72 hours, on one printable page
Which one do you need?
- The fasting calculator answers "when can I eat?": choose your plan and when you finished eating, and it shows when your fast ends and when your eating window closes.
- The stage calculator answers "what is my body doing now?": enter when you last ate to see how long you've fasted and the stage your body may be in.
- The water, protein and BMI calculators help you plan your eating window and your drinks, and the weight goal calculator shows when you could reach your goal at a steady pace.
- The printable fasting schedule and the stages chart are made for the fridge door.
Not sure which plan to choose? Compare every plan, from a gentle 13:11 to a 36-hour fast.
A note on health
Fasting Tracker is designed for general wellness and is not a medical device. Fasting is not right for everyone. If you are pregnant, diabetic, have a history of eating disorders or take medication, talk to your doctor first, and before any extended fast.