How accurate is this pregnancy calculator?

Our pregnancy calculator provides estimates based on common medical formulas (Naegele's rule for LMP, standard gestational periods for other methods). The most accurate due date is typically determined by an early ultrasound performed by your healthcare provider. This calculator is a helpful tool for estimation but should not replace professional medical advice.

What is LMP in pregnancy calculation?

LMP stands for Last Menstrual Period. It refers to the first day of your last period. It's a common starting point for calculating an estimated due date, as a typical pregnancy lasts about 40 weeks (280 days) from the LMP.

Can I use this calculator if I have irregular periods?

If you have irregular periods, calculating based on LMP might be less accurate. In such cases, using an estimated conception date (if known) or an early ultrasound date provided by your doctor will give a more reliable estimate. Our calculator supports these methods. Always confirm with your doctor.

How does the IVF calculation work?

For IVF (In Vitro Fertilization), the due date is calculated based on the date of embryo transfer and the age of the embryo (e.g., 3-day or 5-day). Conception is effectively the day of egg retrieval (transfer date minus embryo age). Our calculator uses this to estimate an equivalent LMP and then the due date (280 days from equivalent LMP).

What are pregnancy trimesters?

Pregnancy is divided into three trimesters, each marking distinct developmental stages: First Trimester: Week 1 to the end of Week 13 (approx. 0-97 days from LMP). Critical organ development occurs. Second Trimester: Week 14 to the end of Week 27 (approx. 98-195 days from LMP). Baby grows rapidly, and you may start feeling movement. Third Trimester: Week 28 to delivery (approx. 196-280+ days from LMP). Baby continues to mature and gain weight, preparing for birth. Our calculator will indicate your current trimester.

Is my data safe with this calculator?

Yes, your data is safe. This pregnancy calculator operates entirely within your web browser. No information you enter is sent to or stored on our servers. Your privacy is important to us. For more details, please see our Privacy Policy .

Ultimate Pregnancy Calculator: Estimate Your Due Date & Track Milestones

Welcome to your go-to resource for navigating the exciting journey of pregnancy! Our Pregnancy Calculator is designed to provide you with an estimated due date and a personalized timeline of your pregnancy. Whether you’re trying to conceive, have just found out you’re pregnant, or are simply curious, this tool offers valuable insights.

Understanding your pregnancy timeline can help you prepare for each stage, from the first trimester to the final countdown. This calculator can estimate your pregnancy schedule based on various inputs: your Last Menstrual Period (LMP), a known Due Date, Conception Date, an Ultrasound scan, or even an IVF transfer date.

Pregnancy Due Date Calculator

Calculate Based On:

First Day of Your Last Period:

Your Known Due Date:

Estimated Conception Date:

Ultrasound Date:

Gestation at Ultrasound (Weeks):

Gestation at Ultrasound (Days):

IVF Transfer Date:

Embryo Age at Transfer:

Your Pregnancy Journey

Key Milestones:

How Our Pregnancy Calculator Works

Our calculator uses established methods to estimate your pregnancy milestones. Simply choose the calculation method that best suits the information you have:

Last Menstrual Period (LMP): This is the most common method. Enter the first day of your last period. A typical pregnancy lasts 280 days (40 weeks) from the LMP.
Known Due Date: If your doctor has already given you an estimated due date (EDD), you can enter it here to see your current progress and other key dates.
Conception Date: If you know the approximate date of conception (often tracked with ovulation kits or fertility awareness methods), this can provide a precise calculation. Pregnancy typically lasts 266 days (38 weeks) from conception.
Ultrasound Date: An early ultrasound is often the most accurate way to date a pregnancy. Enter the date of your ultrasound and the gestational age (in weeks and days) determined at that scan.
IVF Transfer Date: For pregnancies resulting from In Vitro Fertilization, enter your embryo transfer date and the age of the embryo (3-day or 5-day).

Once you input your data and click "Calculate Pregnancy," you'll receive information including:

Your Estimated Due Date (EDD)
Current Gestational Age (how many weeks and days pregnant you are)
Estimated Date of Conception
Your Current Trimester and progress
Key milestone dates, like the approximate end of your first and second trimesters

Understanding Your Pregnancy Term and Due Date

Pregnancy describes the period (approximately 9 months or 40 weeks) during which one or more offspring develop inside a woman. Childbirth typically occurs around 38 weeks after conception, which is about 40 weeks after the last menstrual period. The World Health Organization (WHO) defines a normal full-term pregnancy as lasting between 37 and 42 weeks.

Your healthcare provider will usually give you an estimated due date (EDD) during an early OB-GYN visit, often confirmed or adjusted by an ultrasound. While an EDD is an estimate, the actual length of pregnancy can vary due to factors like maternal age, previous pregnancy lengths, and maternal weight. Studies show that only a small percentage of babies (around 4%) are born on their exact due date, but most (around 90%) arrive within two weeks of it.^1,2

Detecting Pregnancy

Pregnancy can be detected through pregnancy tests or by noticing early symptoms. Common signs include a missed menstrual period, increased basal body temperature, fatigue, nausea (morning sickness), and increased frequency of urination.

Pregnancy tests work by detecting the hormone human chorionic gonadotropin (hCG), which is produced during pregnancy. Clinical blood or urine tests can detect pregnancy as early as 6-8 days after fertilization. Home pregnancy urine tests are widely available and convenient, though clinical blood tests are more sensitive and can detect hCG earlier and in smaller amounts.

Managing Your Pregnancy: Key Considerations

A healthy pregnancy involves careful attention to several factors. Always consult with your healthcare provider for personalized advice.

Medication

Some medications can be harmful during pregnancy. The U.S. Food and Drug Administration (FDA) categorizes drugs (previously A, B, C, D, X; now with more descriptive labeling) based on their potential risk to the fetus. Always discuss any medications (prescription, over-the-counter, or supplements) with your doctor before use during pregnancy.

Healthy Weight Gain

Gaining an appropriate amount of weight is crucial for both mother and baby. The Institute of Medicine (IOM), now the National Academy of Medicine, provides guidelines for pregnancy weight gain based on pre-pregnancy Body Mass Index (BMI). Insufficient or excessive weight gain can lead to complications. For example, for women with a "normal" BMI (18.5-24.9) before pregnancy, a weight gain of 25-35 pounds is generally recommended.³ (Optional: You can add a link here if you create a Pregnancy Weight Gain Calculator).

Exercise

Regular, moderate exercise is generally beneficial during an uncomplicated pregnancy. The American College of Obstetricians and Gynecologists (ACOG) suggests that women with uncomplicated pregnancies can often continue or start moderate-intensity aerobic exercise. It can improve fitness and potentially reduce the risk of C-sections.^4,5 However, always consult your doctor before starting or continuing an exercise program. Stop exercising and consult your doctor if you experience symptoms like vaginal bleeding, dizziness, or decreased fetal movement.

Nutrition

Proper nutrition is vital. Pregnancy increases energy and specific micronutrient needs. Folic acid (Vitamin B9) is crucial for preventing neural tube defects, while DHA omega-3 supports brain development.⁶ A balanced diet rich in fruits, vegetables, lean protein, and whole grains is recommended. Your doctor or a dietitian can provide tailored nutritional guidance.

Related Tools & Resources

Explore more of our helpful tools for your family planning and pregnancy journey:

Disclaimer & Privacy

This Pregnancy Calculator provides estimates based on standard calculations and is intended for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment from a qualified healthcare provider. Always seek the advice of your physician or other qualified health professional with any questions you may have regarding a medical condition or pregnancy. Never disregard professional medical advice or delay in seeking it because of something you have read on this website or results from this calculator.

At [Your Website Name], we are committed to providing helpful and accurate information while respecting your privacy. This calculator processes all data locally in your web browser. No personal information you enter is sent to, or stored on, our servers. Please review our " title="Privacy Policy">Privacy Policy for more details on how we handle data on our website.

References:

Jukic, AM, Baird, DD, Weinberg, CR, et al. (2013). Length of human pregnancy and contributors to its natural variation. Human Reproduction, 28(10), 2848-55.
Moore, K. (2015). How accurate are 'due dates'? BBC News. Retrieved from [Link to BBC article if appropriate or find a similar reliable source]
Institute of Medicine (US) and National Research Council (US) Committee to Reexamine IOM Pregnancy Weight Guidelines. (2009). Weight Gain During Pregnancy: Reexamining the Guidelines. National Academies Press (US).
Davies, GA, Wolfe, LA, Mottola, MF, et al. (2003). Exercise in pregnancy and the postpartum period. Journal of Obstetrics and Gynaecology Canada, 25(6), 516-29. (Or a more recent ACOG guideline)
ACOG Committee Opinion No. 804: Physical Activity and Exercise During Pregnancy and the Postpartum Period. (2020). Obstetrics & Gynecology, 135(4), e178-e188.
Lammi-Keefe, CJ, Couch, SC, Philipson, E. (Eds.). (2008). Handbook of Nutrition and Pregnancy. Humana Press. (Or more recent reputable source on pregnancy nutrition)

Pregnancy Calculator : Artlyo