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Egg Freezing Calculator

Egg freezing is an incredible way to take control of your fertility, giving you the option to have a healthy baby when the time is right for you. It’s no guarantee though. Your chance of having a healthy baby using frozen eggs depends upon many factors, but most importantly:

  1. Your age when you froze your eggs
  2. How many eggs you froze
  3. The expertise of your fertility clinic

We created our Egg Freezing Calculator to give you clarity and help you make confident and informed decisions about your reproductive future.

Want to see what your chances look like? Try the calculator now.

This calculator is intended as a general guide only and does not constitute medical advice. The results are based on internal data from Virtus Health and may not reflect the success rates of other clinics or individual circumstances. Outcomes may vary depending on your personal medical profile, the clinic, and the treating specialist. We recommend speaking with your fertility specialist to understand success rates relevant to your care. For more information on how your chances of success are calculated, please refer to the drop-down section below.

Learn more about egg freezing here

How is my probability calculated?

We evaluate the probability of a live birth per egg for each age group via the following steps:

  1. Thaw survival rate – the probability that a mature cryopreserved egg survives the thawing process
  2. Fertilisation rate – the probability that an egg is successfully fertilised via intra-cytoplasmic sperm injection
  3. Blastulation rate – the probability that a chromosomally-normal fertilised egg progresses to a blastocyst stage embryo that is usable for transfer
  4. Live birth rate – the probability that a transferred embryo results in a live birth


Thaw survival rate of 91.5% has been determined from an analysis of 906 eggs vitrified at Melbourne IVF (a member of Virtus Health) between Jul 2017 and Dec 2022. It was also determined that freeze-thawed eggs which do survive warming have fertilisation, blastulation, and live birth rates similar to non-vitrified eggs.

Fertilisation rate, blastulation rate, and live birth rates have been determined from an analysis of 131,851 eggs from collections performed at Melbourne IVF (a member of Virtus Health) between Jul 2017 and Dec 2023.

  • The sample of 131,851 eggs were all mature, not vitrified, had fertilisation attempted via ICSI (intra-cytoplasmic sperm injection) and did not undergo PGT (pre-implantation genetic testing)
  • Various biological factors influence a patients’ likelihood of producing transferrable embryos and their number of embryo transfers. We normalise success rates per patient to ensure they are representative of the broader population and not impacted by a subset of patients.
  • Not all embryos that are usable for transfer are transferred and our embryologists always select the best embryo available. This introduces a selection bias towards higher quality embryos. We have applied a correction factor of 98.4% to compensate, determined by mapping live birth rates of selected embryos to non-selected embryos of the same embryo grade.


Finally, we assume a binomial (normal) distribution to evaluate the probability of one or multiple children based on the number of eggs and the probability of a live birth per egg.