Wondering how your cycle compares to everyone else's? Enter your numbers and we'll show you where you sit in the population — backed by real stats, not guesswork.
Based on population studies, the average cycle is 28 days with a standard deviation of 3.5 days. The clinically accepted normal range is 21–35 days. Average period duration is 5 days (range 3–7 days).
Why tracking helps
Tracking your cycle over 3–6 months gives you a much more accurate picture of your normal. Cycles can vary month-to-month, so an average across multiple cycles is more meaningful than a single data point.