Ovulation calculator
Discover your most fertile days and understand your cycle personalized for you
Know your window
Discover your most fertile days and understand your cycle personalized for you
Enter your cycle details
Start with the first day of your last period and your average cycle length. Muuse does the rest, showing you exactly when ovulation happens and your peak fertility window.
Why ovulation timing shapes your whole month
Ovulation isn't just about fertility. It's the hinge on which your entire cycle turns—affecting your energy, mood, skin, and how your body responds to exercise and food.
Peak fertility arrives once per cycle
Your hormones shift your appetite and mood
Knowing your window lets you plan ahead
Questions
Everything you need to know about predicting your fertile window
Ovulation typically happens 14 days before your next period, though this varies. The fertile window spans five days before ovulation and the day of ovulation itself. Muuse calculates this based on your cycle length and patterns.
Our predictions are based on established fertility science and your personal cycle data. No calculator is 100 percent accurate—cycles shift with stress, travel, and health. Tracking over time makes predictions more precise.
This tool identifies your fertile window. If you're using fertility awareness for contraception, pair it with other methods and consult a healthcare provider. Muuse is designed to help you understand your body, not replace medical advice.
Irregular cycles make prediction harder but not impossible. Track several months of data to find patterns. Muuse learns from your history and adjusts predictions accordingly as you log more information.
Hormonal contraceptives suppress ovulation, so traditional ovulation prediction doesn't apply. This tool works best for natural cycles. If you're on hormonal birth control, Muuse still tracks your pill schedule and withdrawal bleeds.
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