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Pregnancy & Baby

Free pregnancy & baby calculators: ovulation, due date, how far along, conception, period, hCG doubling, pregnancy weight gain, baby cost and more — with the methods explained.

18 calculators Free and online

📌 About Pregnancy & Baby

From planning a pregnancy to budgeting for a newborn, almost every milestone comes down to a date or a number. This category covers the whole journey: figure out when you ovulate and your fertile window, pin down a conception or due date, see exactly how far along you are, track your cycle, and check an hCG doubling time — then plan ahead with first-year baby costs, the cost of raising a child to 18, diapers and breast-milk storage.

Each tool uses an established method and names it — ACOG and Mayo Clinic for cycle and dating math, the IOM 2009 guidelines for pregnancy weight gain, CDC guidance for milk storage, and the USDA framework for child-rearing costs. Results are estimates for general information only and don't replace your provider's care; an early ultrasound gives the most reliable pregnancy dating.

  • Find your fertile window and ovulation day, then time a pregnancy test
  • Estimate a due date, conception date, and exactly how far along you are
  • Predict your next periods and check an hCG doubling time
  • See IOM-recommended pregnancy weight gain for your pre-pregnancy BMI
  • Budget a baby's first year, the cost to age 18, and diapers
  • Look up CDC breast-milk storage times and just-for-fun gender and eye-color predictions

🧮 Calculators in this category

Conception

Ovulation Calculator — Fertile Window, Ovulation Day & Next 3 Cycles
Find your most fertile days from your last period and cycle length: your estimated ovulation day, the 6-day fertile window around it, and projections for the next three cycles.
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Fertility by Age Calculator — Natural Conception Odds Per Cycle & Per Year
Estimate your natural monthly and cumulative chance of conceiving by maternal age, with population odds over 6 and 12 months drawn from ACOG and ASRM data.
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Implantation Calculator — Implantation Date, Window & Earliest Test Day
Estimate when a fertilized egg likely implants — the 6-to-12-day window after ovulation — and the earliest day a pregnancy test could realistically turn positive, from your last period and cycle length.
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Pregnancy Test Calculator — When to Take a Pregnancy Test
Find the most accurate day to take a home pregnancy test — and the earliest day worth trying — from the first day of your last period and your cycle length.
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Conception Date Calculator — Estimate When You Conceived
Estimate the date you most likely conceived — working backward from your due date or forward from your last period — and see the few-day conception window around ovulation.
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Pregnancy

How Far Along Am I Calculator — Pregnancy Weeks, Days & Trimester
Find out exactly how far along you are right now — your gestational age in weeks and days, the trimester you're in today, and how many days remain to your 40-week due date, from your last period or your known due date.
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Pregnancy Weight Gain Calculator — IOM Recommended Gain by BMI
See how much weight to gain in pregnancy based on your pre-pregnancy BMI, using the Institute of Medicine (IOM) 2009 guidelines — total range, weekly target, and a check on where you are today.
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hCG Doubling Time Calculator — Two-Value Beta hCG Rise & Doubling Hours
Enter two quantitative beta hCG blood results and the hours between draws to get your hCG doubling time in hours, the percent rise, and the projected two-day rise.
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Due Date Calculator — Pregnancy Due Date, Conception & Gestational Age
Estimate your pregnancy due date from your last menstrual period using Naegele's rule, plus your conception date, how many weeks along you are, and your trimester.
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Family Budget

Baby Cost Calculator — First-Year Cost of a Newborn
Add up what a newborn really costs in year one: diapers and wipes, feeding, clothing, nursery gear, healthcare, and childcare — with a low, typical, and high US estimate plus a monthly figure.
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Cost of Raising a Child Calculator — Birth to Age 18 (USDA Method)
Estimate the total cost of raising a child from birth to age 18 using the USDA Expenditures on Children by Families framework, broken down by income tier, number of children, per year, per month, and by spending category.
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Diaper Calculator — How Many Diapers & Total Diaper Cost to Potty Training
Estimate how many diapers your baby will go through from today until potty training, and what they'll cost per month and in total at your price per diaper.
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Just for Fun

Baby Eye Color Calculator — Predict Your Baby's Eye Color from Both Parents
Estimate the odds your baby will have brown, green, or blue eyes from both parents' eye colors, using the classic simplified two-gene inheritance model — for fun, not a guarantee.
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Chinese Gender Predictor — Boy or Girl by the Chinese Lunar Chart
Read the traditional Chinese gender chart for fun: cross your lunar age at conception with the lunar month you conceived to get a Boy or Girl prediction. About a coin-flip — not science.
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Newborn Care

Breast Milk Storage Calculator — Use-By Times for Pumped Milk (CDC Rules)
Enter when you pumped and where the milk is stored, and get the exact use-by date and time using the CDC's 4-4-6 breast milk storage guidelines for healthy, full-term babies.
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Menstrual Cycle

Safe Period Calculator — Fertile Window & Safe Days by the Calendar Method
Estimate your fertile window and the relatively safer days of your cycle using the calendar (rhythm) method — shortest cycle minus 18, longest cycle minus 11 — from your last period.
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Period Calculator — Predict Your Next 6 Periods & Fertile Days
Predict the start dates of your next six periods — and the estimated ovulation day in each — from the first day of your last period, your average cycle length, and how long your period lasts.
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Due Date

IVF Due Date Calculator — Day 3 & Day 5 Embryo Transfer
Estimate your baby's due date from an IVF embryo transfer — works for both Day 3 embryos and Day 5 blastocysts — plus your current gestational age in weeks and trimester.
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📝 Related articles

Read more about this topic on our blog.

How Much Does a Baby Cost the First Year? A Real US Budget
A baby's first year typically costs $13,000 to $25,000 in the US, and childcare is by far the biggest line. Here's a real breakdown plus ways to save.
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How Far Along Am I? Pregnancy Weeks and Trimesters Explained
Pregnancy is counted in weeks and days from your last period, not from conception. Here's how to figure out how far along you are and which trimester you're in.
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When Should You Take a Pregnancy Test for Accurate Results?
The most reliable time to take a pregnancy test is the first day of your missed period. Here's the hCG timeline, early-test odds, and why false negatives happen.
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Ovulation and Your Fertile Window, Explained
Ovulation drives a roughly 6-day fertile window each cycle. Here's how to estimate it, the real signs of ovulation, and why cycle length changes everything.
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❓ Frequently asked questions

How is a due date calculated?

For a natural pregnancy, the due date is your last menstrual period plus 280 days (40 weeks), adjusted if your cycle isn't 28 days. For IVF, it's counted from the transfer date based on the embryo's age.

When am I most fertile?

Ovulation happens about 14 days before your next period, and your fertile window is roughly the five days before ovulation plus ovulation day. The ovulation calculator maps those days from your last period and cycle length.

When is the best day to take a pregnancy test?

The most accurate day is the first day of your missed period (last period plus your cycle length). A test can sometimes detect hCG a few days earlier, but with lower accuracy — the pregnancy test calculator shows both dates.

Are these pregnancy and baby calculators medical advice?

No. They're informational estimates built on standard, named methods (ACOG, Mayo, IOM, CDC, USDA). Use them to understand the timeline and plan ahead, but rely on your healthcare provider for dating, diagnosis and care decisions.