About IVF Due Date Calculator

What This Calculator Does

IVF Due Date Calculator is a free, comprehensive tool designed specifically for individuals and couples who have conceived through in vitro fertilization (IVF) or frozen embryo transfer (FET). Unlike standard pregnancy calculators that rely on last menstrual period (LMP) dating, our calculator uses the precise information available from IVF procedures to provide more accurate pregnancy dating.

The calculator includes three specialized tools, each addressing different needs during your IVF pregnancy journey:

Due Date Calculator

The primary calculator determines your estimated due date (EDD) based on your embryo transfer date and the age of your embryo at transfer. It calculates your current gestational age, identifies which trimester you're in, shows your pregnancy progress as a percentage, and displays days since transfer and until your due date. The calculator also generates a personalized timeline of key pregnancy milestones, from your beta HCG blood test through to your due date.

Pregnancy Timeline

The timeline tab provides a visual, week-by-week overview of your entire pregnancy. It displays all 40 weeks organized by trimester, highlights your current week, and shows which weeks you've already completed. This gives you a clear picture of where you are in your pregnancy journey and what lies ahead.

Gestational Age Calculator

This tool calculates your exact gestational age for any specific date—past, present, or future. This is particularly useful when you need to know your gestational age for a specific appointment, when filling out medical forms, or when you want to see how far along you'll be at a future date. It displays gestational age in weeks and days, total days, your trimester, and days remaining until your due date.

The Science Behind It

IVF due date calculation differs from natural conception dating because we have precise information about when fertilization occurred. In natural conception, the exact fertilization date is unknown, so pregnancy dating uses the last menstrual period (LMP) as a starting point—assuming ovulation occurred on day 14 of the cycle. This assumption isn't always accurate.

With IVF, we know the exact day of egg retrieval (when fertilization occurs) and the exact day of embryo transfer. This precision allows for more accurate pregnancy dating. Medical convention establishes gestational age by counting from a theoretical LMP that would be 14 days before conception. Since we know the embryo's age at transfer, we can calculate the exact gestational age.

The calculator uses the following established formulas based on embryo age at transfer:

• Day 3 embryo: Gestational age at transfer is 2 weeks and 3 days (17 days). Add 263 days to transfer date for due date.
• Day 5 embryo (blastocyst): Gestational age at transfer is 2 weeks and 5 days (19 days). Add 261 days to transfer date for due date.
• Day 6 embryo: Gestational age at transfer is 2 weeks and 6 days (20 days). Add 260 days to transfer date for due date.

These calculations align with the medical standard of a 280-day (40-week) pregnancy from LMP, adjusted for the known embryo age at the time of transfer.

Who This Calculator Is For

This calculator is designed for anyone who has conceived through assisted reproductive technology (ART), including:

• Individuals who have undergone fresh IVF embryo transfer
• Those who have had frozen embryo transfer (FET) procedures
• Couples using donor eggs or embryos where the transfer date is known
• Gestational carriers and intended parents tracking pregnancy milestones
• Healthcare providers looking for a quick reference tool for IVF dating
• Anyone preparing for an IVF cycle who wants to understand how dating will work

The calculator works for transfers involving day 3 cleavage-stage embryos as well as day 5 or day 6 blastocysts—the most common transfer types performed today.

Our Methodology

The calculations in this tool follow the methodology used by fertility clinics and reproductive endocrinologists worldwide. The approach is based on the medical consensus that pregnancy duration is 280 days (40 weeks) from the first day of the last menstrual period (LMP).

Since IVF patients may not have a traditional LMP that corresponds to their pregnancy, we calculate a "theoretical LMP" by working backward from the known embryo age at transfer. The embryo's age plus 14 days gives the gestational age at transfer, and this allows us to establish consistent dating that matches what would be seen on early ultrasound measurements.

Trimester divisions follow standard obstetric definitions: the first trimester spans weeks 1 through 12, the second trimester covers weeks 13 through 27, and the third trimester begins at week 28 and continues until delivery.

Pregnancy milestones displayed in the calculator reflect typical timing for standard obstetric care, including the beta HCG blood test (typically 9-14 days post-transfer), first ultrasound (around 6-7 weeks), anatomy scan (18-22 weeks), viability threshold (24 weeks), and full-term status (37 weeks).

Limitations and Disclaimer

While this calculator uses medically accepted formulas, it provides estimates only and should not replace professional medical advice. Important limitations to understand:

• Individual variation exists: Not all pregnancies progress identically. Your healthcare provider may adjust your due date based on ultrasound measurements, particularly if early scans show development that differs from transfer-based dating by more than 5-7 days.
• Due dates are estimates: Only about 5% of babies are born on their exact due date. Most full-term births occur within two weeks before or after the estimated due date.
• This is not medical advice: The information provided by this calculator is for educational and planning purposes only. Always consult your fertility clinic, reproductive endocrinologist, or obstetrician for official pregnancy dating and medical guidance.
• Multiple pregnancies differ: If you're carrying twins or higher-order multiples, your care timeline and delivery expectations will differ from singleton pregnancies.
• Complications require professional care: If you experience any concerning symptoms or complications, contact your healthcare provider immediately regardless of what any calculator indicates.

How to Use the Calculator

Using the Due Date Calculator

1. Navigate to the calculator and ensure the "Due Date" tab is selected.
2. Enter your embryo transfer date in the date field. This is the date your embryo was placed in the uterus.
3. Select your embryo age at transfer: Day 3 (cleavage stage), Day 5 (blastocyst), or Day 6 (extended blastocyst culture).
4. Optionally indicate whether this was a fresh or frozen transfer—this doesn't affect the calculation but helps you keep track.
5. Click "Calculate Due Date" to see your results, including estimated due date, current gestational age, trimester, and pregnancy milestones.

Using the Timeline Tab

1. Select the "Timeline" tab from the calculator.
2. Enter your embryo transfer date.
3. Select your embryo age at transfer (Day 3, 5, or 6).
4. Click "Generate Timeline" to see your week-by-week pregnancy overview with your current week highlighted.

Using the Gestational Age Calculator

1. Select the "Gestational Age" tab.
2. Enter your embryo transfer date.
3. Optionally enter a specific date you want to calculate for. Leave blank to calculate for today.
4. Select your embryo age at transfer.
5. Click "Calculate Gestational Age" to see the exact weeks and days for your specified date.

Why We Built This

We created this calculator to provide a genuinely useful, free resource for the IVF community. Our guiding principles:

• Completely free: No paywalls, no premium features, no subscription required. All calculator functions are available to everyone at no cost.
• No signup required: Use the calculator immediately without creating an account, providing an email address, or sharing any personal information.
• Privacy-focused: All calculations happen entirely in your web browser. Your transfer dates, results, and any information you enter never leave your device and are never transmitted to any server.
• No data stored: We don't collect, store, or track your pregnancy information. When you close the page, your entered data disappears.
• No ads or tracking: The calculator exists to be helpful, not to monetize your attention or data.

The IVF journey can be emotionally and financially demanding. We believe that simple tools to help you understand and track your pregnancy should be freely available to everyone, without barriers or hidden costs.

IVF Global Statistics

In vitro fertilization has transformed reproductive medicine since its inception. Today, IVF is a mainstream fertility treatment performed in clinics around the world, helping millions of families realize their dreams of parenthood.

Calculator Accuracy Comparison

Different pregnancy dating methods offer varying levels of precision. Because IVF provides exact knowledge of fertilization timing, IVF-specific calculators deliver superior accuracy compared to traditional approaches.

How Our Calculator Compares

We designed IVF Date Calculator with four core principles that set it apart from other pregnancy tools and general-purpose due date calculators.

IVF Technology Timeline

The science of assisted reproduction has advanced dramatically over the past four decades. Each breakthrough has improved success rates and expanded access to fertility treatments worldwide.

Data Protection Features

Your privacy is fundamental to how this calculator was built. Here is a transparent breakdown of what data is and is not collected when you use our tool.

Calculation Methodology Comparison

The accuracy of pregnancy dating varies significantly depending on the method used. The chart below compares the relative accuracy of common dating approaches, showing why IVF-specific calculation provides the most precise results.

Accuracy reflects how closely each method's estimated due date typically matches the actual delivery date within a ±7-day window, based on published obstetric research. IVF transfer dating achieves the highest precision because the exact date of fertilization and embryo age are known.

Questions or Feedback

If you have questions about how the calculator works or suggestions for improvement, we'd love to hear from you. Visit our contact page to get in touch.

For medical questions about your specific pregnancy, please consult your fertility clinic or healthcare provider.