๐ธ Cycle Predictor
Enter your last period start date to calculate
This is an estimate only. Cycles vary between individuals โ consult a doctor for medical guidance.
Enter your last period date and average cycle length to get a predicted date for your next period and an estimated fertile window. Use it as a statistical guide for tracking your cycle or planning ahead, not a guarantee.
How to use
- Enter the start date of your last period.
- Enter your average cycle length and period length.
- See your predicted next period date and estimated fertile window.
FAQ
How is the fertile window calculated?
It's estimated by working backward from your predicted next period, based on the general window in which ovulation is thought to occur.
Is it accurate if my cycle is irregular?
If your cycle is irregular, predictions from this formula may drift from your actual cycle. Treat it as a general guide and consult a gynecologist if needed.
How many cycles ahead can I see predictions for?
You can see predictions for several upcoming cycles, not just the very next one.
Is this useful for fertility planning?
It can serve as a general reference for your fertile window, but it's based purely on statistical calculation. If you're actively planning, combining it with basal body temperature tracking and a doctor's guidance is recommended.
What is the period length field used for?
It's used to show the length of your period on the cycle calendar and schedule view.