Pregnancy Calculator
Calculate your estimated due date, current gestational age in weeks/days, and key trimester milestones.
Pregnancy Calculator
Obstetric Dating & 40-Week Milestone EngineThe Pregnancy Calculator can estimate a pregnancy schedule based on the provided due date, last period date, ultrasound date, conception date, or IVF transfer date.
• Choose your calculation baseline: Due Date (Default), Last Period (LMP), Conception Date, Ultrasound, or IVF Transfer Date.
• View your estimated due date (EDD), real-time gestational age (weeks/days), trimester breakdown, and interactive 40-week fetal size guide.
40-Week Gestational Timeline
57.1% CompletedKey Gestational Milestone Dates
| Milestone | Date Range / Target | Weeks |
|---|---|---|
| Estimated Conception | Apr 5, 2026 | Week 2 |
| First Trimester Ends | Jun 27, 2026 | Week 13 |
| Second Trimester Ends | Oct 3, 2026 | Week 27 |
| Full Term Reached | Dec 6, 2026 | Week 37 |
| Estimated Due Date | Dec 27, 2026 | Week 40 |
Complete 40-Week Fetal Growth & Milestone Schedule
Weekly fetal fruit size comparisons, lengths, weights, and physiological milestones calculated from your LMP (Mar 22, 2026).
Eyebrows, eyelashes, and hair well-defined; senses of touch and spatial orientation maturing.
Related Fertility & Obstetric Calculators
Pregnancy Term, Gestational Dating & Due Date Accuracy
Standard obstetric care calculates human gestation from the first day of the Last Menstrual Period (LMP) rather than the conception date, because the onset of menses is typically a known objective date.
Adds 1 year, subtracts 3 months, and adds 7 days to the first day of LMP (or 280 total days). Adjusts for cycle lengths deviating from 28 days.
Crown-Rump Length (CRL) measured via ultrasound between 8 and 13 weeks is the most accurate clinical method (±3–5 days).
Understanding Pregnancy Calculator & Formula
The Pregnancy Calculator on CalculatorScale.com is engineered to deliver instant, mathematically verified calculations conforming strictly to standard institutional equations. Whether planning long-term investments, managing household budgets, tracking clinical fitness targets, analyzing academic genetics, calculating veterinary dosages, or converting dimensional units, every calculation updates dynamically in real time without lag.
Every formula used in this tool adheres to certified international standards, including World Health Organization biometric metrics, veterinary clinical guidelines, NIST physical conversion constants, and standard biological equations. Results are computed entirely client-side inside your browser with complete data privacy, ensuring your sensitive numbers and statistics never leave your device.
Our calculators are 100% free with no registration, subscriptions, or paywalls required. You can toggle between imperial and metric units, customize input parameters, export calculation summaries, or embed this calculator directly into your own website or blog.
How to Use the Pregnancy Calculator
- 1 Select your calculation method: Last Menstrual Period (LMP), Ultrasound dating, Conception date, or IVF transfer date.
- 2 Enter the date and your typical menstrual cycle length (default 28 days).
- 3 Click "Calculate ▶️" to generate your estimated due date, current gestational week, current trimester, fetal developmental milestones, and countdown timeline.
Pregnancy Calculator — Frequently Asked Questions
Q1 How is the estimated due date (EDD) calculated? ▾
The due date is estimated using Naegele's rule: 280 days (40 weeks) from the first day of your last menstrual period (LMP), assuming an average 28-day cycle with ovulation on day 14.
Q2 How accurate is the estimated due date? ▾
Only about 4% to 5% of babies are born on their exact due date. However, roughly 80% of babies arrive within 10 days before or after the estimated date.
Q3 How are pregnancy trimesters divided? ▾
Pregnancy is divided into three trimesters: First trimester (weeks 1–13), Second trimester (weeks 14–27), and Third trimester (week 28 to delivery).
Q4 What if my menstrual cycle length is not 28 days? ▾
If your cycle is longer or shorter than 28 days, our calculator adjusts the estimated ovulation date accordingly (e.g., subtracting days for shorter cycles or adding days for longer cycles).
More in Gynecology & pregnancy calculators
Pregnancy Conception Calculator
Medical GradeEstimate your most probable conception date, 6-day fertile intercourse window, and gestational milestone timeline using Due Date, LMP, or Ultrasound dating.
Due Date Calculator
Clinical GradeCalculate your estimated delivery date (EDD), current gestational age, trimester dates, and 40-week milestone calendar using LMP, ultrasound, conception date, or IVF transfer.
Pregnancy Weight Gain Calculator
Calculate and track recommended total and week-by-week gestational weight gain targets based on pre-pregnancy BMI and IOM guidelines.
Ovulation Calculator
Fertility SuiteCalculate your exact ovulation day, 6-day fertile window, peak conception dates, and multi-cycle pregnancy planning calendar.
Conception Calculator
Conception SuiteCalculate your most likely conception window, peak ovulation date, pregnancy test timing, and projected full-term due date.
Period Calculator
Cycle SuiteCalculate your next period start and end dates, countdown, estimated ovulation, and multi-month menstrual cycle calendar.
Explore All 4,700+ Calculators by Category
Genetics, molecular laboratory science, veterinary dosages, animal gestation, agronomy, and forestry.
Stoichiometry, chemical solutions, thermodynamics, kinetics, electrochemistry, and organic reactions.
Concrete, roofing, brick, framing, lumber spans, driveway paving, gravel, and material specifications.
Precision metric and imperial unit converters for length, area, volume, mass, pressure, temperature, and speed.
Carbon footprint, solar energy payback, tree sequestration, recycling offsets, and sustainable living metrics.
Travel durations, clothing and shoe sizes, fuel economy, home budgeting, sleep cycles, and daily routines.
Mortgage amortization, compound interest, loans, retirement planning, taxes, investments, and salary projections.
Culinary volume-to-weight conversions, baking hydration, ingredient scaling, pizza dough, and party food planning.
BMI, daily caloric needs (TDEE/BMR), body fat percentage, pregnancy due dates, clinical dosage, and pediatric metrics.
Scientific calculators, fractions, percentages, geometry, trigonometry, algebra, linear systems, and matrices.
Kinematics, Newtonian dynamics, thermodynamics, fluid mechanics, electromagnetism, optics, and relativity.
Heart rate training zones, running pace, triathlon pacing, cycling power, calories burned, and 1RM lifting benchmarks.
Standard deviation, normal distribution (Z-scores), confidence intervals, sample size, and probability odds.
Education GPA, photography exposures, music BPM, data storage, network bandwidth, and specialty calculations.