All Period and Fertility Calculators
Browse our complete collection of 26 free, private period, ovulation, pregnancy dating, and fertility calculators. 100% browser-based. Zero data stored.
Period & Menstrual Cycle Calculators
Track cycle lengths, predict upcoming periods, and explore the four biological cycle phases.
Period Cycle Phases Calculator
Find today's menstrual phase, cycle day, and days remaining in each phase with an interactive 4-phase biological cycle ring. Fast and private.
Period Calculator for Irregular Periods
Predict your next period range and fertile window using your shortest and longest cycle lengths. Designed for irregular cycles and PCOS.
Follicular Phase Calculator
Calculate the estimated start and end dates of your follicular phase, total phase length, and key hormonal changes. Private, client-side tool.
Monthly Period Cycle Calculator
Generate a 12-month forward period planner with predicted start dates, fertile windows, and a printable overview. 100% private in browser.
Accurate Period Calculator
Enter 3 to 13 past period start dates to calculate your weighted average cycle length and personalized prediction window with high accuracy.
Period Cycle Calculator
Find your estimated cycle day and menstrual phase for any calendar date, with a visual horizontal timeline of your next 6 menstrual cycles.
Period Cycle Length Calculator
Measure your menstrual cycle lengths from multiple period dates, with mean, median, cycle variability analysis, and visual charts.
Menstrual Cycle Calculator
Explore a complete breakdown of all four menstrual cycle phases, estimated hormone rhythms, and next period dates with interactive charts.
Period Phase Calculator
Determine which cycle phase you were in or will be in for any past, present, or future calendar date. Client-side and private.
Luteal Phase Calculator
Calculate your luteal phase length from confirmed ovulation to period start. Understand luteal phase defect signs and cycle health.
PMS Date Calculator
Predict your upcoming PMS symptom window, explore the difference between PMS and PMDD, and track cycle timing privately on your device.
Late Period Calculator
Determine how many days late your period is, review common non-pregnancy causes, and find optimal timing for home pregnancy testing.
Ovulation & Fertility Calculators
Find your 6-day fertile window, peak conception dates, and plan trying to conceive.
Ovulation Calculator
Calculate your estimated ovulation date, 6-day fertile window, and peak conception days. 100% private, client-side calculator with zero tracking.
Fertility Calculator
Plan conception with your personalised fertile window, peak fertility days, recommended intercourse timing, and LH test dates. 100% private.
Safe Days Calculator
Identify lower and higher conception probability days using the Ogino-Knaus calendar rule. Educational fertility awareness with zero data saved.
Ovulation Day Calculator
Pinpoint your estimated ovulation day and cycle day from your period date, cycle length, and luteal phase settings. Instant & private.
Ovulation After Miscarriage Calculator
Estimate when ovulation and menstrual cycles may return after pregnancy loss, with supportive clinical context and wider uncertainty bands.
Printable Ovulation Calendar
Generate a printable 3-month ovulation calendar displaying estimated ovulation dates, fertile windows, and predicted period start days.
Pregnancy & Due Date Calculators
Calculate estimated due dates from LMP, conception, ultrasound, or IVF embryo transfer.
Due Date Calculator
Calculate your estimated baby due date, current gestational age, trimester, and weekly milestones from your LMP, conception, or ultrasound date.
Conception Calculator
Estimate your probable conception dates and fertile window from your last period, ultrasound, or due date. Pure client-side calculations.
Implantation Calculator
Calculate your estimated implantation window, earliest pregnancy test date, and clinical milestones based on ovulation or conception timing.
IVF Due Date Calculator
Calculate your estimated baby due date and gestational timeline from Day 3, Day 5, Day 6 embryo transfers, egg retrieval, or IUI timing.
Pregnancy Test Date Calculator
Find the earliest possible and most reliable dates to take a home pregnancy test based on ovulation timing or your missed period date.
Pregnancy Week Calculator
Calculate how many weeks and days pregnant you are today, identify your current trimester, and view baby developmental milestones.
Wellness, Nutrition & Symptoms
Calculate energy requirements and explore evidence-based health guidance.
Pregnancy Calorie Calculator
Calculate your daily energy and calorie needs by trimester using the Mifflin-St Jeor formula and activity level guidelines. 100% private.
Pregnancy Weight Gain Calculator
Calculate healthy target weight gain ranges and weekly gain rates across each trimester based on your pre-pregnancy BMI and IOM guidance.