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Due Date Calculator

Calculate your expected due date and track pregnancy stages accurately

💖 Calculate Due Date
About Due Date Calculator

The Due Date Calculator is an accurate medical tool that helps pregnant women calculate their expected delivery date based on the first day of their last menstrual period or conception date. This calculator uses the famous Naegele's Rule, which is adopted by most doctors worldwide to determine the due date.

Knowing your expected due date is extremely important for both the mother and doctor, as it helps track fetal growth properly, schedule necessary medical checkups, and plan for delivery. The calculator provides detailed information about your current pregnancy week, which trimester you're in, and major milestones throughout your pregnancy.

Our Due Date Calculator offers two calculation methods: the first from the first day of your last menstrual period (LMP), and the second from the conception date. Both methods provide accurate results, but the first method is more commonly used in medical clinics. Remember that the calculated due date is an estimate, as only 5% of women deliver on their exact due date, while 80% deliver within two weeks before or after the expected date.

How to Use the Due Date Calculator
  1. Select the appropriate calculation method (from last menstrual period or conception date)
  2. Enter the first day of your last menstrual period or conception date
  3. Click "Calculate Due Date" button to get results
  4. Review the expected due date, current pregnancy week, and trimester
  5. Check the pregnancy milestones table to know important dates
Frequently Asked Questions

The calculator uses Naegele's Rule: it adds 280 days (40 weeks) to the first day of your last menstrual period. If using conception date, it adds 266 days (38 weeks).

The due date is an estimate. Only 5% of women deliver on their exact due date. About 80% deliver within two weeks before or after the expected date. The date serves as a guide for medical follow-up.

First trimester: Weeks 1-12 (major organs form). Second trimester: Weeks 13-26 (rapid growth). Third trimester: Weeks 27-40 (growth completion and preparation for birth).

It's recommended to visit the doctor as soon as pregnancy is discovered, usually at weeks 6-8. The first visit includes pregnancy confirmation, blood tests, and accurate due date determination using ultrasound.

If your cycle is irregular, it may be difficult to accurately determine the due date. In this case, use the conception date calculation method, or consult your doctor to accurately determine the date using early ultrasound.

Yes, the doctor may adjust the due date based on early ultrasound (especially at weeks 8-13) which provides accurate fetal size measurements and gives a more precise date estimate.

Preterm delivery: before week 37. Full-term delivery: weeks 37-42. Post-term delivery: after week 42. If pregnancy exceeds week 41, the doctor may decide to induce labor.

Usually: monthly until week 28, every two weeks until week 36, weekly until delivery. These schedules may change based on your health and doctor's recommendations.
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Due Date Calculator: Estimate Your Expected Delivery

This calculator estimates your expected due date and shows where you are in the pregnancy, including the current week and trimester. You can calculate from the first day of your last menstrual period (LMP) or from a known conception date, and the tool counts forward to give you a target date and a clear timeline.

The most common method uses the last menstrual period and a typical pregnancy length of about 40 weeks, or 280 days, from that first day. Because cycle lengths and ovulation timing vary from person to person, the result is an estimate rather than a fixed appointment. Only a small share of babies arrive exactly on the predicted day; most deliveries occur in the couple of weeks around it, which is completely normal.

How to Use the Estimate

Use the due date as a planning anchor for appointments, work leave, and preparing for the baby, while remembering that an ultrasound dating scan from your clinic is usually the most accurate way to confirm timing, especially if your cycles are irregular. Tracking the week and trimester also helps you follow general milestones in development.

This tool provides general educational information and does not replace professional medical care. For decisions about your pregnancy, monitoring, and delivery, always rely on your doctor, midwife, or qualified healthcare provider.