FET Due Date Calculator
Calculate your due date from a frozen embryo transfer (FET). Supports Day 3, Day 5, and Day 6 frozen transfers using the same math fertility clinics use.
Reviewed by Pregora Editorial Team · Last updated 2026-04-26
Tip: Select "Frozen (FET)" in the calculator below for FET-specific labelling.
Wednesday, December 23, 2026
Day 5 fresh transfer240 days to go
Note:IVF dating is usually more accurate than LMP-based estimates because the embryo age is known precisely. Trust your fertility clinic's date for medical decisions.
Frequently asked questions
Is the FET due date different from a fresh IVF due date?▾
Mathematically no — the embryo's age determines the gestational age, not whether it was previously frozen. A Day 5 FET on a given date gives the same due date as a Day 5 fresh transfer on that date.
How is FET due date calculated?▾
Add 266 days to conception (egg retrieval/fertilization), then subtract the embryo age at transfer. For Day 3 FET: add 263 days to transfer date. For Day 5: 261 days. For Day 6: 260 days.
Why does the embryo age matter?▾
Because it tells us how many days post-conception the embryo was when transferred. The standard pregnancy length is 266 days from conception, regardless of when transfer occurred.
What about Day 7 transfers?▾
Day 7 FET is uncommon but mathematically uses the same formula: transfer date + 259 days. Most clinics transfer at Day 5 or earlier.
Related tools
Due Date Calculator
Estimate your pregnancy due date from last period, conception, ultrasound, or a known due date.
Pregnancy Week Calculator
How far along am I? Find your current week, trimester, and major pregnancy milestones.
Ovulation Calculator
Find your fertile window, peak ovulation day, and next 6 ovulation dates from your last period.
Conception Calculator
Find when you most likely conceived from your last period, due date, or ultrasound.
Reverse Due Date Calculator
Already have a due date? Work backward to find conception date, LMP, and pregnancy timeline.
IVF Due Date Calculator
Calculate due date from embryo transfer — Day 3, Day 5, Day 6 transfers and FET cycles.
Trimester Calculator
What trimester am I in? Find your current trimester (1st, 2nd, or 3rd) and trimester boundaries.
Implantation Calculator
When does implantation happen? Find your implantation window (6-12 days after conception) and earliest test date.
Pregnancy Test Calculator
When can I take a pregnancy test? Earliest reliable date for standard, early-detection, and blood tests.
Chinese Gender Predictor
Predict baby gender using the traditional 24×12 lunar age chart. For entertainment only — not science.
Pregnancy Weight Gain Calculator
Healthy weight-gain range based on pre-pregnancy BMI and current week, using IOM guidelines.