Pregnancy Calculator

Use it for simple educational checks, trend tracking, or planning tasks like these: Estimate an expected due date from the first day of the last menstrual period. Check pregnancy week and gestational age today. It can help you understand a number, but it cannot explain your whole health situation.

Enter the first day of the last menstrual period, not the last day bleeding occurred. Cycle length means the usual number of days from one period start to the next; use 28 only if that is close for you. If the LMP is uncertain, cycles are irregular, bleeding may not have been a true period, or a clinician has already dated the pregnancy, use the clinician or ultrasound date instead.

In plain language: The calculator uses Naegele-style dating: due date = first day of LMP + 280 days + (cycle length - 28 days). It estimates ovulation or conception near LMP + cycle length - 14 days and counts gestational age from LMP to today. Read the result together with the notes on the page, because health and fitness numbers often need personal context.

Read the due date as an estimated delivery date from calendar math, not a guarantee of when birth will happen. Gestational age is counted from LMP, so it is usually about two weeks more than conception age. The conception and trimester lines are planning references, and an early ultrasound or clinician review can update the official date.

Pregnancy dating usually counts gestational age from the first day of the last menstrual period. That means the gestational-age number is often about two weeks ahead of the estimated conception age.

The calculator shifts the due date by the difference from 28 days. A 32-day cycle moves the estimate about four days later, while a 26-day cycle moves it about two days earlier. Irregular cycles make calendar dating less reliable.

No. The conception line is an estimate near ovulation, not proof of an exact day, intercourse date, or parentage. Fertilization timing, sperm survival, ovulation shifts, and dating uncertainty all matter.

Use clinician dating when your care team gives you an official due date, especially after an early ultrasound, uncertain LMP, irregular cycles, bleeding that may not have been a true period, IVF, multiples, or medical concerns.

No. This page provides an educational estimate only. Talk with a qualified health professional before making medical, pregnancy, nutrition, medication, or safety decisions. Use the calculator as a learning tool, then ask a qualified professional about decisions that affect care, pregnancy, medication, nutrition, or safety.

Check the units, date, and personal details before reading the answer. For example, pounds and kilograms, inches and centimeters, or a wrong activity level can change the result quickly. If the number feels surprising, rerun it slowly and compare it with the examples.

No. The calculator runs in your browser tab. Recent answers stay only on the page while you use it, and they are not sent to a server.