Cycle calculators & trackers
Five free tools to understand your cycle, predict your period, and check your PMS symptoms. No account required.
Cycle Calculator
Most popularEnter your last period date and cycle length to predict your next period, ovulation day, and fertile window.
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Ovulation Calculator
Find your fertile window and peak ovulation day. Useful for understanding your most fertile days.
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Period Due Date Calculator
See exactly when your next period is due and how many days away it is — with an ovulation window too.
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Luteal Phase Calculator
Calculate the length of your luteal phase and find out if it falls within the normal range.
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PMS Symptom Checker
QuizRate 10 premenstrual symptoms on a 1–5 scale and get a PMS severity score with guidance on next steps.
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Track across multiple cycles
Calculators give you a one-time estimate. Dawn Phase tracks your actual patterns and improves predictions every cycle.
Start tracking free →Free · No credit card required
For informational purposes only. Dawn Phase is not a medical device, not contraception, and not a substitute for advice from a qualified healthcare provider.