Every tool, in one place
All 38 calculators
Free, science-backed, ad-supported. Every calculator cites its sources, shows its math, and tells you when the answer is uncertain. Pick a stage to browse:
Trying to conceive
Category page →Cycle, ovulation, fertility, and IVF tools — for the planning + trying stretch.
- Ovulation CalendarSix months of fertile windows, periods, and ovulation days at a glance.
- Period CalculatorPredicts your next six cycles plus expected ovulation days.
- Conception & Ovulation CalculatorFind your fertile window, ovulation day, and the six-day conception window.
- Twin Probability CalculatorTwin pregnancy probability from family history, age, BMI, parity, and IVF status.
- Time to Conception CalculatorMonths until likely pregnancy by age and cycle regularity. Dunson–Baird fecundability data.
- Fertility Costs CalculatorEstimated total cost ranges for IUI, IVF, egg freezing, and embryo freezing — by US region.
- US Surrogacy Cost CalculatorItemized US surrogacy cost estimator by state, agency vs. independent.
- IVF Success Rate CalculatorPer-cycle and cumulative IVF live birth rates from SART national data, by age + diagnosis.
Pregnancy
Category page →From positive test through delivery — dates, growth, weight, kicks, hCG.
- Due Date CalculatorCalculate your baby's due date with cycle-length adjustment. Naegele's rule, done honestly.
- How Far Along Am I?Pregnancy week calculator: weeks + days, trimester, and what is developing now.
- IVF Due Date CalculatorExact IVF due date by transfer or retrieval type — Day-3, Day-5, Day-6, FET, fresh transfer, IUI.
- hCG Doubling Time CalculatorBeta hCG doubling time with Kadar 1981 and Barnhart 2004 reference ranges.
- Fundal Height CalculatorExpected fundal height in cm by gestational week with 10th–90th percentile range.
- Pregnancy Weight Gain CalculatorIOM-recommended pregnancy weight gain by pre-pregnancy BMI with week-by-week tracking.
- Baby Kick CounterCount to ten kicks. Saves between sessions. The standard reassurance check.
- Baby Movement TimelinePersonalized week-by-week timeline of fetal movement milestones — first flutter to regular kicks.
- Birth Weight PredictorPredict your baby's birth weight from maternal pre-pregnancy weight, parity, GA, and fetal sex.
Trait predictions
Category page →Eye color, hair, height, blood type, names — the genetics-based projections.
- Eye Color PredictorPolygenic eye-color predictor with optional grandparents — far better than the 1907 Punnett square.
- Baby Hair Color PredictorPolygenic hair-color projection from parents' childhood + current hair, including the redhead carrier path.
- Curly Hair PredictorCurly hair probability based on parent texture and grandparent traits.
- Baby Blood Type PredictorABO + Rh inheritance with full Mendelian probability distribution from both parents.
- Adult Height PredictorProject your child's adult height from parent heights using the Mid-Parental formula. ±2″ confidence range.
- Baby Growth Percentile CalculatorWHO + CDC growth percentile from a single measurement, with clinical-grade LMS math.
- Baby Name PopularitySee how popular any baby name has been since 1880, using the official SSA dataset.
- Baby Name CompatibilityDoes the name sound right with your last name? Rhythm, syllables, and flow scored.
Genetic risks
Category page →Inheritance odds for handedness, color blindness, lactose, allergies, myopia.
- Left-Handedness ProbabilityAbout 1 in 10. Slightly more if you are. Probability with family history.
- Color Blindness ProbabilityX-linked color blindness probability — your maternal line tells the story.
- Lactose Intolerance ProbabilityLactose intolerance probability by ancestry. Most adults globally are.
- Baby Allergy Risk CalculatorEczema, asthma, hay fever, and food allergy probability based on parents and siblings.
- Cilantro-Soap Gene PredictorWill cilantro taste like soap? OR6A2 / rs72921001 inheritance probability.
- Nearsightedness Risk PredictorLifetime myopia risk and most likely age of onset, with the modifiable-factor delta from outdoor + screen time.
Newborn & beyond
Category page →Once they're here — feeding, sleep, dosage, diapers, sizing, solids.
- Formula Feeding CalculatorAAP-aligned formula amounts: ounces per day, per feeding, and how often, by baby weight + age.
- Breast Milk Storage CalculatorCDC breast milk storage time limits at room temperature, fridge, freezer, and after thawing.
- Solids Readiness CalculatorAAP and WHO 8-sign readiness checklist for starting solid foods.
- Diaper CalculatorDiaper size by weight plus daily, weekly, monthly, and yearly count, with annual cost estimate.
- Baby Sleep CalculatorTotal sleep, number of naps, and wake-window length by age. AASM-aligned, Iglowstein norms.
- Baby Clothes Size by AgeBrand-consensus clothing size by age with weight and height ranges.
- Children's Tylenol & Motrin DosageAAP-aligned acetaminophen and ibuprofen doses by child weight, exactly as printed on the bottle.