IVF Due Date Calculator

Due date from embryo transfer day for day 2, 3, 5, and 6 transfers.

What it does

IVF dating skips the guesswork of natural conception. Because the lab knows the embryo age to the day, the due date counts forward from transfer instead of backward from a possibly misremembered period. The result is the most precise estimated date in obstetrics.

The tool above needs two facts: the transfer date and the embryo age. Day 5 blastocysts add 261 days, day 3 embryos add 263, and the formula generalizes to transfer plus (266 minus embryo age). It also reports gestational age at transfer and the equivalent LMP for forms that still ask.

The default walks a day 5 transfer on March 1 2026 to Tuesday November 17 2026, at 2 weeks 5 days gestational age on transfer day, equivalent to an LMP of February 10 2026. Every figure was checked against the ACOG committee opinion on dating before publishing.

Precision is not a promise of punctuality. Full term spans 39 to 41 weeks, first babies often run late, and twins or complications move plans earlier. Keep every scan appointment, since first trimester ultrasound still confirms ART dating and catches multiples.

This page explains dating math only. Cycle questions, bleeding, medication timing, and risk belong with the fertility clinic and the obstetrician, who date from the full record.

How to use

1. Pick the calendar date embryos were placed.
2. Select the embryo age: day 2, 3, 5, or 6.
3. Read the estimated due date first.
4. Read gestational age at transfer for clinic forms.
5. Copy the equivalent LMP anywhere a form demands one.
6. Confirm everything at the first ultrasound visit.

Formula

EDD

Estimated due date, 40 weeks from equivalent LMP.

transfer

Calendar date of embryo placement.

embryo age

Days from fertilization to transfer (2, 3, 5, or 6).

266

Conception to delivery interval in days (38 weeks).

Natural dating adds 280 days to LMP because it assumes ovulation on day 14. IVF replaces the fuzzy first 14 plus embryo days with known values: gestational age at transfer equals 14 days plus embryo age, so a day 5 transfer is already 19 days along. Fresh and frozen transfers use identical math; only the age at placement matters.

Worked example

Reference table

Limits

• Assumes a 266 day conception to delivery interval; real gestations vary by weeks.
• Frozen, fresh, donor, and tested embryos share the math only when the age at transfer is right.
• Does not predict multiples, preterm risk, or delivery mode.
• Day 2 and day 6 transfers are uncommon; confirm the age on the lab report.

Common mistakes

• Adding 280 days to transfer, which double counts the embryo days.
• Selecting day 5 when the report says day 6, shifting the date by one day.
• Using retrieval day instead of transfer day.
• Treating the EDD as a deadline instead of a 5 week window.
• Filling LMP forms with the transfer date.

Try it yourself

Quick checks. Answers sit tucked under each question.

Questions

Sources

• ACOG Committee Opinion 700: Methods for Estimating the Due Date
• CDC: ART success rates and monitoring

Related calculators