Answer first
What this calculator tells you
Estimate a due date from an embryo transfer date and the age of the embryo at transfer. Plan around a due date counted from the transfer, and expect your clinic's dating to be the final word. Formula: Due date = transfer date + 266 days − embryo age at transfer; gestational age on transfer day = 14 + embryo age. At the worked-example inputs, the estimated due date is February 17, 2027. Holding every other input steady, moving embryo transfer date from May 18, 2026 to June 15, 2026 moves the result from February 3, 2027 to March 3, 2027.
Transparent method
The formula
Plan around a due date counted from the transfer, and expect your clinic's dating to be the final word.
Worked example
Example inputs
How to interpret the result
With IVF, the day of conception is known, so the date counts from the transfer and not from a last period. A day 5 embryo transferred on June 1 is dated 19 days into the pregnancy that day. The due date follows 261 days later, which is 266 minus the 5 days the embryo had already lived. A day 3 embryo pushes the date two days later, since it is two days younger.
At the worked-example inputs the gestational age on transfer day (days) is 19. It rises with embryo age at transfer (days); embryo transfer date does not move it.
Gestational age counted from the last period is an estimate that assumes a regular cycle and an accurate date. A dating ultrasound can move it by days, and your clinician's dating is the one that counts for care and for the due date.
Before you rely on it
What to check
Confirm the embryo age with your clinic. Day 3 and day 5 transfers use different offsets, and the wrong one moves the date by two days.
The common error
Where people go wrong with IVF due date calculator
Counting 280 days from the transfer date. That ignores the days the embryo had already lived and the two weeks of dating before conception, and it lands nearly three weeks late.
Sensitivity evidence
How embryo transfer date changes the estimated due date
Holding every other input at the worked-example value, moving embryo transfer date from May 18, 2026 to June 15, 2026 moves the estimated due date from February 3, 2027 to March 3, 2027: a spread of 28.0 days.
| Embryo transfer date | Estimated due date | Gestational age on transfer day (days) |
|---|---|---|
| May 18, 2026 | February 3, 2027 | 19 |
| May 25, 2026 | February 10, 2027 | 19 |
| June 1, 2026worked example | February 17, 2027 | 19 |
| June 8, 2026 | February 24, 2027 | 19 |
| June 15, 2026 | March 3, 2027 | 19 |
Every input, tested
Which input moves the gestational age on transfer day (days) most
Of the 2 inputs, only embryo age at transfer (days) moves the gestational age on transfer day (days): switching embryo age at transfer (days) changes the gestational age on transfer day (days): day 3 embryo gives 17; day 5 embryo gives 19; day 6 embryo gives 20. Embryo transfer date does not change it at all.
| Input | Tested from | To | Gestational age on transfer day (days) at each end | Swing |
|---|---|---|---|---|
| Embryo age at transfer (days) | Day 3 embryo | Day 6 embryo | 17 to 20 | 3 (16%) |
| Embryo transfer date | May 25, 2026 | June 8, 2026 | 19 to 19 | none |
Step by step
The worked example, input by input
| Input | Value used | What it means |
|---|---|---|
| Embryo transfer date | June 1, 2026 | Enter the embryo transfer date used in this calculation. |
| Embryo age at transfer (days) | Day 5 embryo | Day 3 and day 5 embryos are the most common. |
| Estimated due date | February 17, 2027 | |
| Gestational age on transfer day (days) | 19 | |
Inputs, definitions and assumptions
Embryo transfer date
Enter the embryo transfer date used in this calculation. The prefilled worked-example value is June 1, 2026.
Embryo age at transfer (days)
Day 3 and day 5 embryos are the most common. The prefilled worked-example value is Day 5 embryo.
How to use this calculator
- 1Verify the inputs. Gather embryo transfer date and embryo age at transfer (days) from your own documents; the prefilled values are examples.
- 2Save a baseline. The worked example puts the estimated due date at February 17, 2027. Store your own version of it as Scenario A.
- 3Test one change. Start with embryo age at transfer (days), the input with the biggest effect here: switching embryo age at transfer (days) changes the gestational age on transfer day (days): day 3 embryo gives 17; day 5 embryo gives 19; day 6 embryo gives 20.
- 4Check the boundary. Read the interpretation boundary above before acting on the result.
People also ask
Frequently asked questions
How do you calculate IVF due date?
Due date = transfer date + 266 days − embryo age at transfer; gestational age on transfer day = 14 + embryo age. At the worked-example inputs the estimated due date is February 17, 2027.
What does the IVF due date result mean?
Plan around a due date counted from the transfer, and expect your clinic's dating to be the final word. At the worked-example inputs the gestational age on transfer day (days) is 19. It rises with embryo age at transfer (days); embryo transfer date does not move it.
How much does embryo transfer date change the estimated due date?
Holding every other input at the worked-example value, moving embryo transfer date from May 18, 2026 to June 15, 2026 moves the estimated due date from February 3, 2027 to March 3, 2027, a spread of 28.0 days.
What are the limits of this IVF due date calculator?
Gestational age counted from the last period is an estimate that assumes a regular cycle and an accurate date. A dating ultrasound can move it by days, and your clinician's dating is the one that counts for care and for the due date. The tables on this page test embryo transfer date only from May 18, 2026 to June 15, 2026; a value outside that range is not tabulated here.
How much does embryo age at transfer (days) matter in the IVF due date calculator?
The worked example uses Day 5 embryo. With the other inputs left at the worked example, switching embryo age at transfer (days) changes the gestational age on transfer day (days): day 3 embryo gives 17; day 5 embryo gives 19; day 6 embryo gives 20.
What is the difference between LDL, HDL and non-HDL cholesterol?
LDL carries cholesterol out to tissues and is the main target for lowering. HDL carries it back toward the liver. Non-HDL is total minus HDL, and it counts every particle that can build up in arteries.
Does my blood pressure change through the day?
Yes. It is usually lower in sleep, rises on waking and moves with activity, stress, caffeine and posture. A few calm readings at the same time of day give a truer picture than one.
How is an IVF due date different from a regular one?
The conception date is known, so it counts from the transfer instead of the last period. The embryo's age at transfer sets the offset, and your clinic's dating takes priority over any calculator.
How far ahead can a period be predicted?
The next period is the most reliable estimate, and each one after it is less certain. Cycles vary by a few days, and the error adds up across several months.
Sources and evidence
Free Calculators Online is independent and is not affiliated with or endorsed by the source organizations. Educational estimates only.