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Period Calculator

Predict your next period, understand your cycle phases, and discover your fertile window — all in seconds.

Your data stays right here in your browser. We never store or send anything.

Tell us about your cycle

Enter your details and we'll map out your upcoming cycle. All fields are based on averages — it's okay if you're not sure!

The first day of your most recent period
days
Most cycles are 21–35 days. 28 is the average.
days
Periods usually last 2–8 days. 5 is most common.
Your Predictions

Your Upcoming Periods

Based on your cycle, here are your next three predicted periods.

Cycle Phases

Your Cycle Breakdown

Your cycle has four beautiful phases. Here's what's happening in each one.

Calendar View

Your Cycle Calendar

See your cycle phases color-coded across the coming months.

Menstrual
Follicular
Ovulation
Luteal
Fertile Window
Helpful Tips

Cycle Care Tips

A few gentle reminders to help you work with your body, not against it.

Track Consistently

Mark the first day of your period each month — even if it's irregular. Over 3–6 cycles, patterns often emerge that help you understand your body's rhythm. Apps and calendars both work great!

Nourish Each Phase

Your nutritional needs shift throughout your cycle. During menstruation, focus on iron-rich foods like leafy greens and lentils. During the follicular phase, lighter meals with fermented foods can support rising estrogen levels.

Honour Your Energy

It's normal to feel more energetic around ovulation and quieter during the luteal phase. Schedule demanding tasks during your energy peaks, and allow yourself rest when your body asks for it. You're not lazy — you're cyclical!

Know When to See a Doctor

If your periods are consistently shorter than 21 days or longer than 35 days, if you soak through a pad/tampon every hour, or if you experience severe pain that disrupts daily life — please reach out to a healthcare provider. You deserve answers and relief.

Disclaimer: This calculator provides estimates based on average cycle patterns. Every body is unique, and actual dates may vary. This tool is not a substitute for professional medical advice, and should not be relied upon as a method of contraception or fertility planning. Please consult a healthcare provider for personalized guidance.