Egg Freezing Success Rate Calculator
Enter your age at the time of egg freezing and the number of mature eggs you plan to freeze. The calculator uses age-stratified thaw-survival, blastocyst-development, and euploid-embryo rates from current clinical data to estimate your probability of achieving one, two, or three live births. Results update instantly as you adjust the inputs.
How the egg freezing success rate is calculated
Each frozen mature egg passes through four sequential steps before a live birth is possible: thawing (survival), fertilisation and culture (blastocyst development), chromosomal screening (euploidy), and embryo transfer. The probability of a live birth per egg is the product of the rates at each stage. For a 32-year-old, that works out to roughly 92% survival, 33% blastocyst rate, 60% euploid rate, and 70% birth-per-transfer rate, giving about 12-15% per egg. Because each egg represents an independent attempt, the probability of at least one success from n eggs follows a binomial distribution: 1 minus the chance every single egg fails.
Why age matters so much
Age affects both the quantity and quality of eggs. As you get older, fewer eggs are retrieved per cycle, and those that are retrieved are more likely to carry chromosomal abnormalities (aneuploidy). For someone under 30, roughly 69% of blastocysts are chromosomally normal; by age 40 that figure falls to around 27-35%. This is why the number of eggs needed to reach the same probability roughly doubles between age 30 and age 40. The decline is gradual before 37 and steeper after that. Freezing at a younger age is more efficient: fewer retrieval cycles, lower total cost, and higher per-egg success rates.
How many eggs do you actually need?
The answer depends on your age and how many children you hope to have. Studies consistently show that having 15 or more mature eggs frozen makes a meaningful difference, particularly for women over 35. For a 32-year-old targeting one child, around 12-15 eggs give a 70-80% chance; for a 38-year-old, that rises to 20-25 eggs. For two children, roughly double those figures. These are population averages, and individual factors like ovarian reserve (AMH level), antral follicle count, and clinic-specific lab quality all shift your personal estimate. Multiple retrieval cycles are common and can be combined.
What the pipeline numbers mean
The calculator breaks your eggs into four expected outcomes: eggs surviving thaw, blastocysts formed, chromosomally normal embryos, and live births. These are averages, not guarantees. A single retrieval of 12 eggs at age 32 might yield about 11 surviving eggs, 4 blastocysts, and 2 euploid embryos on average, though actual numbers vary widely. Each euploid embryo has roughly a 60-70% chance of implanting and leading to a live birth, so 2 euploid embryos gives a strong chance of at least one success. The pipeline framing helps set realistic expectations and plan for the possibility that a second retrieval cycle may be needed.
Egg freezing success rates by age group
| Age group | Per-egg live birth rate | Eggs for 70% chance (1 child) | Eggs for 80% chance (1 child) | Eggs for 70% chance (2 children) |
|---|---|---|---|---|
| Under 30 | 16.9% | 7 | 9 | 42 |
| 30-34 | 14.5% | 8 | 11 | 57 |
| 35-37 | 11.3% | 11 | 14 | 94 |
| 38-40 | 8.7% | 14 | 18 | 99 |
| 41-42 | 5.0% | 24 | 32 | 99 |
| Over 42 | 3.0% | 40 | 53 | 99 |
Per-egg live-birth efficiency and expected outcomes across age groups. Source: Spring Fertility clinic data (2026), 13,533 warmed eggs.
Frequently asked questions
What is the success rate for egg freezing?
Success rates vary primarily by age. For women under 35, each frozen mature egg has approximately a 12-17% chance of resulting in a live birth when all steps are included (thaw survival, fertilisation, embryo development, and transfer). By age 38-40, that drops to around 8-9%, and above 42 it falls below 5%. Freezing more eggs at a younger age is the most reliable way to improve the odds.
How many eggs do I need to freeze for one baby?
A widely cited guideline is 15-20 mature eggs for a 70-80% chance of one live birth for women in their early 30s. For women 35-37 the same target requires 20-25 eggs, and for women 38-40 it rises to around 25-30 eggs. These are estimates based on published clinic data. Your reproductive endocrinologist can give more personalised guidance based on your AMH, antral follicle count, and clinic success rates.
What is the difference between mature and immature eggs?
Only mature (MII) eggs can be successfully fertilised. During a retrieval cycle, some eggs are collected at an immature stage (MI or GV) and cannot be frozen with viable results. When your clinic reports the number of eggs retrieved, ask specifically how many were mature, as that is the number used in probability calculations like this one.
Does the number of retrieval cycles matter?
Yes. Many women do more than one egg freezing cycle to accumulate enough mature eggs. The eggs from multiple cycles can be combined. The calculator treats the total number of mature eggs frozen, regardless of how many cycles were needed to collect them. Each additional cycle roughly adds the same number of eggs as the first, so a second cycle at the same age carries the same per-egg success rate.
What is PGT-A and should I consider it?
Preimplantation Genetic Testing for Aneuploidy (PGT-A) screens blastocysts for chromosomal abnormalities before transfer. It avoids transferring embryos unlikely to implant or that might lead to miscarriage. It is most commonly recommended for women over 37, those with recurrent pregnancy loss, or those with a prior aneuploid pregnancy. PGT-A adds cost per cycle but can reduce the number of failed transfers.
How long can frozen eggs be stored?
Eggs stored in liquid nitrogen at clinically certified facilities can remain viable for many years. Studies have found no significant decline in outcomes between eggs used after 2 years versus 5 years of storage. Long-term data beyond 10 years is more limited, but current evidence suggests no major degradation with proper storage. Annual storage fees typically range from a few hundred to several hundred dollars per year.
Are these success rates the same as my clinic will quote?
Not necessarily. The rates used here come from published large-scale datasets (Spring Fertility 2026, Doyle et al., Cobo et al.). Individual clinic results can be higher or lower depending on lab quality, stimulation protocols, and patient selection. Always ask your clinic for their own age-stratified live-birth-per-egg data, as that is the most accurate predictor for your specific situation.