Free cycle tools

Calculators, quizzes, and guides to understand your cycle, then sync your food, workouts, and skincare to it.

Calculators

  • Period Calculator — Use this free period calculator to predict when your next period is due. Enter the first day of your last period and your average cycle length, and we will estimate your next three periods.
  • Ovulation Calculator — This free ovulation calculator estimates the day you ovulate and your fertile window, the days each cycle when conception is most likely.
  • Cycle Phase Calculator — Not sure which cycle phase you are in right now? Enter your last period date and cycle length to find out instantly, along with what is happening to your hormones today.
  • Cycle Length Calculator — Your cycle length is the number of days from the first day of one period to the first day of the next. This calculator works it out from two recent period start dates.
  • Luteal Phase Calculator — The luteal phase is the stretch between ovulation and your next period. This calculator estimates when it starts, when it ends, and how long it lasts.

Quizzes

  • What's My Cycle Phase? — Not sure where you are in your cycle? Answer a few quick questions about how you feel today and we will estimate your phase based on your symptoms.
  • What's My PMS Type? — PMS is not one thing. Some people get hit hardest by mood, others by bloating, cravings, or exhaustion. Knowing your pattern is the first step to easing it.
  • Are My Hormones Balanced? — Hormone imbalance rarely announces itself. It shows up as small, everyday things: energy crashes, mood dips, stubborn skin, or cycles that feel unpredictable.

Best foods for your cycle

Cycle glossary