Whether you’re undergoing a frozen embryo transfer (FET) as part of your fertility journey or supporting someone who is, one of the most exciting questions is: When is the baby due? Our FET Due Date Calculator is a quick, reliable, and hassle-free tool designed to give you that answer instantly. With just one input—your transfer date—you’ll receive an accurate due date based on the standard gestational timeline for FET pregnancies.
FET Due Date Calculator
What Is a FET Due Date Calculator?
The FET Due Date Calculator is a web-based tool that estimates your pregnancy due date based on the date your frozen embryo was transferred. Unlike natural conception, where the fertilization date is unknown, FET provides a precise timeline that allows for more accurate due date estimation. This tool takes the guesswork out of planning by automatically adding 266 days (the average gestational period from embryo transfer to due date) to your selected transfer date.
✅ How to Use the FET Due Date Calculator – Step-by-Step Guide
Using this calculator is incredibly simple. Follow these steps:
- Select the Transfer Date
Click on the date input field labeled “FET Transfer Date” and choose the exact date your embryo transfer took place. - Click “Calculate”
Press the “Calculate” button to instantly compute your estimated due date. - View Your Results
The “Estimated Due Date” will appear below the calculator. It’s presented in a full, readable format like “May 10, 2026.” - Reset (if needed)
Want to run another calculation? Just click the “Reset” button to start fresh.
🧪 Example: See the Calculator in Action
Let’s walk through a practical example.
- Scenario: You had your frozen embryo transferred on August 1, 2025.
- Action: Select that date in the calendar and hit “Calculate.”
- Result: The calculator adds 266 days, and your estimated due date will be April 24, 2026.
Simple, fast, and accurate.
🎯 Why Use a Due Date Calculator for FET?
Unlike natural conception, FET gives a precise transfer date, making due date calculation more reliable. This tool is especially beneficial because:
- 🧭 It provides clarity and reassurance.
- 🧑⚕️ It helps with prenatal care scheduling.
- 📅 It aids in planning work, travel, and life events.
- 💬 It supports informed conversations with your fertility or OB-GYN specialist.
🔍 How Is the Due Date Calculated?
The tool uses a fixed interval of 266 days (or 38 weeks) from the day of embryo transfer. This is based on medical standards for blastocyst-stage embryos, which are typically transferred 5 days after fertilization.
It assumes:
- The embryo is a Day 5 blastocyst.
- The pregnancy is singleton (not twins or multiples).
- The embryo implants shortly after transfer.
For earlier-stage embryos (Day 3), some clinicians might add 2 extra days, but 266 days remains the general rule for most transfers.
💡 Helpful Tips for FET Pregnancy
- Keep track of milestones: After your due date, track key moments like your first ultrasound, anatomy scan, and glucose testing.
- Talk to your doctor: Always confirm your due date with your fertility clinic or OB-GYN. This tool offers an estimate, not a medical verdict.
- Know embryo age: If your embryo was frozen earlier or later in development, ask your clinic if adjustments to due date estimation are needed.
❓ Frequently Asked Questions (FAQs)
1. What is a frozen embryo transfer (FET)?
A frozen embryo transfer involves thawing and transferring a previously frozen embryo into the uterus during an IVF cycle.
2. How is a due date for FET different from natural conception?
Natural conception due dates are calculated from the last menstrual period, whereas FET due dates are based on the known transfer date, offering greater precision.
3. What does the calculator assume about embryo stage?
The calculator assumes a Day 5 blastocyst embryo was transferred.
4. Can I use this calculator for Day 3 embryos?
Yes, but note the result may be off by about 2 days. Consult your fertility provider for adjustments.
5. What if I transferred multiple embryos?
The due date remains the same regardless of the number of embryos transferred, but pregnancy progression may vary with multiples.
6. Is the due date from FET more accurate than from LMP?
Yes, because the exact transfer date is known, unlike the often-estimated ovulation date in natural cycles.
7. Does embryo freezing duration affect the due date?
No, the length of time the embryo was frozen doesn’t change gestational age once implanted.
8. Can implantation delay affect the accuracy?
Implantation usually happens within a few days of transfer, so slight delays have minimal impact on the due date.
9. How many days after FET is the due date calculated?
266 days (38 weeks) is the standard, reflecting post-transfer gestation for blastocysts.
10. Can I use this tool for donor embryo transfers?
Yes. As long as the embryo transfer date is known, the origin doesn’t affect due date estimation.
11. Is this tool suitable for frozen egg transfers?
No. Frozen egg transfers involve fertilization post-thawing, so timing differs from embryo transfers.
12. Do I still need an ultrasound to confirm the due date?
Yes. This tool is a guideline, and your healthcare provider will confirm the date based on early ultrasounds.
13. What time zone does the tool use for dates?
It uses your browser’s local date format and time zone.
14. Is the due date exact?
No due date is 100% exact. Only about 5% of babies are born on their due date. It’s an estimate.
15. Can I use this calculator on mobile devices?
Yes, the calculator is fully responsive and works on smartphones and tablets.
16. What if I don’t remember my exact FET date?
Try to retrieve this information from your clinic. Precision matters for due date estimation.
17. Can I bookmark or share the tool?
Absolutely! This tool is web-based and can be easily shared with others undergoing FET.
18. Does the calculator store my data?
No. It runs entirely on your browser and does not save or transmit personal data.
19. Can this tool help with planning maternity leave?
Yes. Knowing your due date early helps with leave planning, childcare, and other logistics.
20. Is this calculator medically certified?
No. It’s intended for informational use only and does not replace professional medical advice.
🤱 Final Thoughts
The FET Due Date Calculator is a must-have companion for anyone going through IVF with frozen embryo transfers. It provides instant insight into your pregnancy timeline, helping you plan, prepare, and celebrate this next chapter with more confidence and clarity.