Extended Fast Planner
Set a length, see your finish time, and use an educational timeline to orient the fast.
This planner turns a fast length into a clear finish time and a map of common fasting stages. The milestone timings are educational ranges, not live body measurements, a prescription, or a promise that everyone responds the same way.
How long is your fast?
60h
When do you start?
—
You finish
60h
Length
Deeper ketosis range
State at the end
Educational stage timeline
16h · Fuel-use shift range
24h · Ketosis range begins
48h · Deeper ketosis range
60h · FastNow target
Educational estimate only. Extended fasting is not for everyone — talk to a healthcare professional first, especially if you are pregnant, underweight, take medication, or have a health condition.