Periods

How long a period lasts, how heavy it is and when it arrives can differ from person to person and from month to month. Here you will find plain answers to the questions people ask most about periods.

Guides

• How to Predict Your Next PeriodA simple method to estimate your next period: average your recent cycles, add it to your last start date, and plan for a window of a few days.

Tools

• Period calculatorEstimate your next six periods, with start and end dates, from your last period, cycle length and period length.
• Cycle length calculatorWork out your average cycle length, shortest and longest cycle, and how much it varies from your period start dates.

These guides are general wellness information, not medical advice. If something about your cycle or your health worries you, talk to a doctor or midwife.