Private by default
Calculations happen in your browser. We do not save or receive the dates you enter.
Free women’s health tools
Useful answers, without giving away your dates.
Calm, private calculators for planning around your cycle and pregnancy. Everything runs on this page. Your entries are never saved or sent to us.
Choose a calculatorNo accountNothing sent to us16 free tools
16 simple tools
What would you like to estimate?
Use your own dates, get an instant result, then close the page.
Period calculator
Estimate your next six period dates from your recent cycle pattern.
Open →Irregular period calculator
Get a date range instead of a date when your cycles refuse to settle.
Open →Cycle length calculator
Average the days between recent period starts and see the range.
Open →Cycle phase calculator
Place a date in a simplified menstrual, follicular, ovulation, or luteal phase.
Open →Follicular phase calculator
See where your follicular phase starts and ends, and how long it runs.
Open →Ovulation calculator
Estimate a six-day fertile window and likely ovulation date.
Open →Fertility calculator
Rank every fertile day by its measured chance of conception.
Open →Safe days calculator
Map the calendar method across your cycle, with its real failure rate.
Open →BBT chart
Log your morning temperature and watch a thermal shift appear.
Open →Implantation calculator
Estimate the implantation window and when a test could work.
Open →Conception calculator
Work backwards to a conception window from any date you already know.
Open →Pregnancy due date calculator
Estimate a due date from your last period or a known conception date.
Open →Pregnancy week calculator
See an estimated gestational week, day, trimester, and due date.
Open →IVF due date calculator
Estimate a due date from a day-3 or day-5 embryo transfer.
Open →Ovulation after miscarriage calculator
See when ovulation and a first period tend to return after a loss.
Open →Pregnancy calorie calculator
Estimate daily calories and protein for your trimester.
Open →Made the Flowy way
Your body is not a certainty machine.
Clear about uncertainty
Results are estimates, with plain-language limits instead of false precision.
Grounded in guidance
Methods link to public guidance from established women’s-health organizations.
These tools provide educational estimates, not diagnosis, medical advice, or birth control. Contact a qualified healthcare professional about symptoms or concerns.