Free Tools

Free Tools for Your Cycle

Simple and reliable calculators to better understand your body, anticipate your period, identify your fertility window and track your health daily.

Each calculator is based on recognized medical methods and works directly in your browser, without registration.

Period Calculator

Predicts your next period based on your cycle length. Anticipate up to 3 cycles ahead.

Identifies your estimated ovulation date and understand your body's signals during this key phase.

Estimates your expected due date and current pregnancy week from your last period.

Calculate your Body Mass Index and discover your health category with personalized recommendations.

Determine your optimal fertility window across multiple cycles to maximize or avoid chances of conception.

Select your current symptoms and discover which phase of your cycle they most likely correspond to.

Rythia's AI gives you personalized predictions, daily briefings and tailored guidance.