Free calculators for periods, ovulation, pregnancy dating, pregnancy nutrition and the months after birth. Each one shows its formula and sources, and nothing you enter is stored.
Women's Health
Fertility and Cycle
Ovulation Calculator
Use this ovulation calculator to estimate your ovulation date, fertile window, and next period from your last period and cycle length.
Period Calculator
Use this period calculator to predict your next period dates from your last period and average cycle length.
Pregnancy Test Calculator
Use this pregnancy test calculator to find when to take a pregnancy test for the most reliable result, and the earliest day a home test might work.
Conception Calculator
Use this conception calculator to estimate when conception most likely happened from your due date, last period, or an ultrasound scan.
Implantation Calculator
Use this implantation calculator to estimate your likely implantation window based on your ovulation date.
Chances of Having Twins Calculator
Use this chances of having twins calculator to estimate your odds of twins from your age, family history and any fertility treatment.
Egg Freezing Calculator
Use this Egg Freezing Calculator to estimate your chance of a live birth from your frozen eggs, or how many eggs you may need for a target chance.
Fertility by Age Calculator
Use this Fertility by Age Calculator to estimate your chance of getting pregnant each cycle, and within 6 and 12 months, at your age.
Clomid Ovulation Calculator
Use this Clomid Ovulation Calculator to estimate when you may ovulate on Clomid, the best days for LH tests and sex, and when to take a pregnancy test.
Luteal Phase Calculator
Use this luteal phase calculator to measure the days from ovulation to your next period and see how your luteal phase compares with typical ranges.
BBT Calculator
Use this BBT calculator to read your basal body temperature chart, find your thermal shift and coverline, and see your likely ovulation day.
Menopause Age Calculator
Use this menopause age calculator to estimate the age range when natural menopause is most likely for you, based on data from over 50,000 women.
Pregnancy
Due Date Calculator
Use this due date calculator to estimate your pregnancy due date from your last period, conception date, or ultrasound.
Pregnancy Weight Gain Calculator
Use this pregnancy weight gain calculator to estimate recommended weight gain from your pre-pregnancy BMI and current week.
HCG Calculator
Use this hCG calculator to check whether the rise between two hCG test results meets the minimum seen in early viable pregnancies.
IVF Due Date Calculator
Use this IVF due date calculator to find your due date from your embryo transfer date and embryo age, for fresh or frozen (FET) transfers.
Pregnancy Calorie Calculator
Use this pregnancy calorie calculator to estimate your daily calorie needs based on your trimester and pre-pregnancy needs.
Pregnancy Macro Calculator
Use this pregnancy macro calculator to calculate protein, carb, and fat targets based on your calorie needs and pregnancy stage.
Baby Eye Color Calculator
Use this Baby Eye Color Calculator to estimate your baby's chance of brown, green or hazel, or blue eyes from parent and grandparent eye colors.
Bishop Score Calculator
Use this Bishop score calculator to add up the findings from your cervical exam and see what your total means for labor induction.
Miscarriage Risk Calculator
Use this Miscarriage Risk Calculator to see the chance your pregnancy continues, week by week, based on your age, history and heartbeat scan.
VBAC Calculator
Use this VBAC calculator to estimate your chance of a vaginal birth after cesarean if you try labor, using the race-free 2021 MFMU model.
Contraction Calculator
Use this contraction calculator to time your contractions, see how long and how far apart they are, and check your last hour against the 5-1-1 rule.
Fetal Weight Percentile Calculator
Use this fetal weight percentile calculator to see where your baby's ultrasound weight estimate falls compared with other babies at the same week.
Crown Rump Length Calculator
Use this crown rump length calculator to turn an early ultrasound CRL measurement into gestational age in weeks and days and an estimated due date.
Fundal Height Calculator
Use this fundal height calculator to check whether your fundal height in cm is within the expected range for your week of pregnancy.
After Birth
Breastfeeding Calorie Calculator
Use this breastfeeding calorie calculator to estimate your daily calorie needs based on your baseline and feeding stage.
Postpartum Weight Loss Calculator
Use this postpartum weight loss calculator to see how much weight you carry compared with before pregnancy and a gentle pace to get back.
Birth Weight Percentile Calculator
Use this Birth Weight Percentile Calculator to see how your baby's birth weight compares with babies born at the same week, and whether it is SGA, AGA or LGA.
Breast Pump Flange Size Calculator
Use this breast pump flange size calculator to turn your nipple diameter in mm into a flange size range and a good size to try first.
Baby Formula Calculator
Use this baby formula calculator to estimate how much formula your baby may need per day and per feeding, based on weight and age.
Breast Milk Calculator
Use this breast milk calculator to estimate how much pumped milk your baby may need per bottle, per day and while you are away.