Calculate your estimated due date from your last period, conception date, IVF transfer, or ultrasound, and track weekly pregnancy milestones.
Calculate your baby's due date to map your progress, unlock trimesters, personalize milestones, and view your custom prenatal calendar.
Every pregnancy is a beautiful, unique adventure. Here is a custom guide to help you follow your body's amazing milestones and trace your little one's growth week-by-week.
Estimated Conception: Jan 22, 2026
Standard pregnancy is calculated at 40 weeks (280 days).
Note: Calculations are based on clinical averages. Due dates are estimates; only about 4% of babies are born on their exact due date.
This tool is for educational purposes only and provides estimated dates based on average timelines. The results are not medical advice and should not be used as a substitute for professional diagnosis, counsel, or care by an obstetrician-gynecologist (OB-GYN), certified midwife, or medical provider. Normal pregnancies can vary by up to two weeks in either direction.
Naegele's Rule estimates a pregnancy due date by adding 280 days (40 weeks) to the first day of the last menstrual period, since gestational age is conventionally measured from LMP...
Understanding gestational calculations, clinical trimesters, and essential guidelines for healthy progression.
Clinically, pregnancy is dated starting from the first day of your Last Menstrual Period (LMP). This means that during the first two weeks of your "gestational age," you are not actually pregnant yet; your body is preparing for ovulation. Due date models (like Naegele's Rule) add 280 days from this LMP base date to approximate a full 40-week term.
Pregnancy is split into three phases. **First Trimester (Weeks 1-13)** is the period of rapid organogenesis, where the basic structures are formed. **Second Trimester (Weeks 14-27)**, often called the "golden phase," brings increased energy and visible baby movements. **Third Trimester (Weeks 28-40+)** focuses on rapid baby growth, lung maturation, and labor preparation.
Getting regular checkups is vital. Early in pregnancy, focus on daily prenatal vitamins containing Folic Acid (400–800 mcg) to help prevent neural tube defects. Monitor hydration, eat nutrient-dense meals, and check in with your provider before starting new exercise regimens. Between weeks 18 and 22, the crucial anatomy ultrasound scan monitors major organs.
The default method adds 280 days (40 weeks) to the first day of your last menstrual period, then adjusts for cycles that are not exactly 28 days by adding or subtracting the difference. This adjustment matters because a longer or shorter cycle shifts the actual ovulation day away from the standard Day 14 assumption.
If you know your conception date, the calculator adds 266 days (38 weeks) instead. For IVF pregnancies, it adds 263 days to a 3-day embryo transfer date or 261 days to a 5-day blastocyst transfer date. For ultrasound dating, it works backward from the scan date using the measured gestational age to project the same 280-day total.
For a last menstrual period starting January 1 with a 30-day cycle, the due date is January 1 plus 280 days plus 2 extra days for the longer-than-average cycle, landing around October 10. A standard 28-day cycle with the same LMP date would land two days earlier, around October 8.
Because due dates are estimates, only a small share of babies are born exactly on the calculated date, and doctors will typically favor an early ultrasound measurement over LMP dates if the two differ by more than about a week. Track how far along you are with the Pregnancy Weight Gain Calculator, and use the Ovulation & Fertility Calculator when planning future pregnancies.
Quick answers about how this tool works.
Standard due date calculations assume a regular 28-day menstrual cycle, with ovulation occurring on Day 14. If your cycle is shorter or longer (e.g. 35 days), ovulation occurs later, meaning your due date will be shifted. The calculator automatically adjusts the due date by adding or subtracting the variance from a 28-day cycle.
For In Vitro Fertilization (IVF) transfers, the due date is calculated based on the embryo transfer date and the age of the embryo. For a 3-day embryo transfer, the due date is transfer date + 263 days. For a 5-day blastocyst transfer, the due date is transfer date + 261 days.
Early ultrasounds (usually performed in the first trimester between weeks 8 and 14) measure the crown-rump length (CRL) of the embryo. This is considered the most accurate method to date a pregnancy, especially for women with irregular menstrual cycles. If the ultrasound estimate differs from the LMP date by more than 7 days, your doctor may adjust your official due date.
A pregnancy due date calculator estimates your baby's expected delivery date based on information such as the first day of your last menstrual period (LMP), conception date, or IVF transfer date. It provides an approximate timeline for pregnancy milestones and fetal development.
A full-term pregnancy typically lasts about 40 weeks (280 days) from the first day of the last menstrual period. Most babies are born between 37 and 42 weeks of pregnancy.
Yes. If you know your conception date, your estimated due date is generally calculated by adding approximately 266 days (38 weeks) to that date. This method can be useful when the conception date is known with reasonable certainty.
Naegele's Rule is a common method used to estimate a due date. It calculates the expected delivery date by adding one year, subtracting three months, and adding seven days to the first day of the last menstrual period.
Yes. Due dates are estimates, and many babies are born before or after the calculated date. Deliveries between 37 and 42 weeks are generally considered within the normal full-term range.
Pregnancy is divided into three trimesters. The first trimester covers weeks 1–13, the second trimester covers weeks 14–27, and the third trimester covers weeks 28–40. Your due date calculation can help determine your current trimester.
Plain-language explainers that sit next to this tool.
Your Estimated Due Date (EDD) can be calculated several ways — from your last menstrual period (LMP), from the date of conception, or from an early ultrasound. Each method has a different precision. This guide explains Naegele's Rule, LMP calculation, and what Indian doctors typically use.
You can only conceive during a 6-day fertile window each cycle. Knowing when that window opens — and how to track it — is the most effective way to improve your chances of getting pregnant. This guide explains the biology and the math behind ovulation tracking.
The first 13 weeks of pregnancy are the most critical period of fetal development. From implantation to the first heartbeat to the NT scan — here is what happens week by week, what symptoms to expect, and which tests are scheduled in trimester one.
A blood pressure reading of "120/80" means nothing until you know the categories. Here is the full AHA chart, how ranges shift with age, and when a number becomes an emergency.
Search 190+ free tools by name, or pick a category below. Every one runs instantly in your browser — no signup, nothing to install.
Tap a star to rate us instantly.
