Due Date Calculator

Estimate your baby's due date and pregnancy milestones.

Due dates are estimates and do not replace prenatal medical care.

Estimated due datePregnancy timelineReviewed for accuracy

Due date calculator

Choose a calculation method and enter the date details you know.

Calculation method

LMP method assumes ovulation around day 14 of a 28-day cycle.

days

Cycle length can shift estimated ovulation and due date.

A clinician may adjust your due date based on ultrasound or medical history.
Most babies are not born exactly on the estimated due date.
This calculator is informational only.

Estimated due date

Tuesday, January 12, 2027

Based on the selected method: Last menstrual period. This is not an exact prediction.

Estimated gestational age

10 weeks, 1 days

Current trimester

First trimester

Days until due date

209 days

Due dates are estimates. Pregnancy care should be guided by qualified healthcare professionals, and ultrasound dating or clinician assessment may revise the date.

Personalized interpretation

Based on last menstrual period, your estimated due date is Tuesday, January 12, 2027.

You may be approximately 10 weeks and 1 days pregnant.

Due dates are estimates. Many pregnancies deliver before or after the calculated date, and your healthcare professional may revise your due date after an ultrasound.

Seek medical care promptly for concerning symptoms such as heavy bleeding, severe pain, fainting, or reduced fetal movement later in pregnancy.

Pregnancy timeline overview

Pregnancy is commonly counted from the first day of the last menstrual period.
A typical estimated pregnancy length is about 40 weeks from LMP.
Conception usually occurs around ovulation.
Pregnancy timelines are estimates, not exact schedules.

Calculation methods explained

Last menstrual period

Uses the first day of your last menstrual period plus cycle-length adjustment.

Conception date

Uses a known or estimated conception date.

IVF transfer

Uses embryo transfer date and embryo age.

LMP vs conception date vs ultrasound dating

LMP is common because many people know their last period date. Conception date can be harder to know exactly.

Ultrasound dating may be used clinically, especially early in pregnancy. Irregular cycles can make LMP-based estimates less accurate.

Trimester guide

First trimester

Weeks 1–13

Early pregnancy is commonly counted from the first day of the last menstrual period.

Second trimester

Weeks 14–27

Many people have anatomy scans and ongoing prenatal visits during this stage.

Third trimester

Weeks 28–40+

The final trimester includes continued growth, monitoring, and birth preparation.

Week boundaries can vary slightly by source. Prenatal care schedules should come from a clinician.

Why due dates can change

Exact delivery date cannot be predicted by a calculator. A due date is a planning estimate, not a deadline.

Irregular cycles
Uncertain LMP date
Ovulation timing
Early ultrasound measurements
IVF details
Clinician assessment
Medical history

Limitations and medical disclaimer

Calculator results are informational only. Dates are estimates, and pregnancy care should be guided by healthcare professionals.

IVF details and complex medical histories should be reviewed clinically.

Seek urgent medical attention for symptoms such as heavy bleeding, severe abdominal pain, fainting, severe headache, chest pain, shortness of breath, or reduced fetal movement later in pregnancy.

Formula / date explanation

LMP method: Estimated Due Date = First Day of Last Menstrual Period + 280 days
Conception method: Estimated Due Date = Conception Date + 266 days

280 days is about 40 weeks from LMP. 266 days is about 38 weeks from conception. IVF due date depends on transfer date and embryo age. Ultrasound or clinician assessment may override calculator estimates.

Frequently Asked Questions