Explore how an age-band live-birth efficiency rate compounds across a number of mature eggs frozen.
Egg freezing details
Use age at freezing and mature egg count
Illustrative model
Modeled probabilities
Illustrative live-birth outcomes
Modeled outcomes will appear here
Enter completed age when eggs were frozen and the number of mature eggs stored.
Modeled chance of at least one live birthBinomial model using an age-band per-egg rate and equal, independent trials
Modeled chance of at least 1 live birth
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Modeled chance of at least 2 live births
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Modeled chance of at least 3 live births
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Illustrative per-egg rate
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The model assumes each egg has the same independent chance and omits thaw survival, fertilization, embryo development, transfer, sperm, uterine, clinic, and personal factors. Published evidence is limited; this estimate should not guide treatment decisions.
This page gives an illustrative mathematical estimate based on age when mature eggs were frozen and the number of frozen mature eggs. It is not an individual fertility prediction. It cannot account for thaw survival, fertilization, embryo development, transfer practices, sperm factors, uterine factors, laboratory performance or a person’s medical history.
The age-specific per-egg figures come from a small cohort summarized in the American Society for Reproductive Medicine’s 2021 guideline: 7.4% under age 30, 7.0% at 30–34, 6.5% at 35–37 and 5.2% at 38–40. The guideline stresses that evidence is limited and insufficient to prescribe an absolute number of eggs for a reasonable live-birth probability. Use clinic-specific counseling for real decisions.
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How to Use This Calculator
Enter completed age at the time the eggs were retrieved and frozen, not current age. The available evidence bands here cover ages 18 through 40.
Enter the number of mature frozen eggs as a whole number from 1 to 100.
Select Calculate. The page applies the age-band rate to a simplified independent-trial model and shows modeled chances of at least one, two and three live births.
The model assumes each egg has the same probability and that outcomes are independent. Real treatment does not satisfy those assumptions perfectly. Eggs may be warmed in groups, embryos share laboratory and patient conditions, and more than one embryo does not necessarily lead to separate births. The percentages should therefore be read as an educational illustration of compounding probability, not a promise, diagnosis, treatment recommendation or reason to delay care.
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Formula Used
Let n be the number of mature frozen eggs and p the illustrative live-birth efficiency per warmed egg for the age band. Under a binomial model:
P(at least 1) = 1 − (1 − p)n
P(at least 2) = 1 − [P(0) + P(1)], and P(at least 3) = 1 − [P(0) + P(1) + P(2)], where P(k) = C(n,k)pk(1−p)n−k. These are model equations, not validated personal prognoses.
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Variables Explained
Inputs and assumptions in the illustrative egg-freezing model
Item
Meaning
Limit or assumption
Age
Completed age when mature eggs were retrieved and frozen.
Whole years from 18 through 40; selects a broad evidence band.
Frozen mature eggs
Number of mature oocytes cryopreserved.
A whole number from 1 through 100; not retrieved eggs of unknown maturity.
p
Published age-band live-birth efficiency per warmed oocyte used for illustration.
7.4%, 7.0%, 6.5% or 5.2%; not clinic-specific.
Modeled percentage
Binomial probability of reaching at least the stated count.
Assumes equal, independent chances and omits many clinical factors.
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Worked Example
For 14 mature eggs frozen at age 32, the illustrative rate is 7.0% per egg. The modeled chance of no live birth is (1 − 0.07)14 = 0.9314, about 36.2%. Therefore, the modeled chance of at least one is 1 − 0.362 = 63.8%. The page shows about 25.6% for at least two and 7.0% for at least three.
Those numbers describe the stated assumptions, not what will happen to an individual. They should not be used to compare clinics, decide how many cycles to undertake or infer the quality of a particular egg cohort.
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Why Use This Calculator?
A higher modeled percentage means the arithmetic assumptions give more routes to the stated outcome. It does not mean a birth is guaranteed, and a lower percentage does not mean pregnancy is impossible. Percentages for “at least two” or “at least three” are cumulative modeled outcomes, not advice about family size or embryo transfer.
ASRM notes that age at freezing and oocyte number are relevant predictors, while available evidence remains limited. A fertility specialist can discuss clinic-specific thaw, fertilization, blastocyst and transfer outcomes and explain how health history and treatment plans apply. Decisions about stimulation, retrieval, storage or using frozen eggs require individualized medical counseling, including procedure risks, cost, timing and alternatives.
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Common Mistakes
Entering current age instead of age at egg retrieval and freezing.
Entering all retrieved eggs when only mature frozen eggs belong in the count.
Reading the percentage as a guarantee or validated personal prognosis.
Assuming eggs are independent and identical in quality because the equation treats them that way.
Comparing the estimate directly with a clinic’s per-transfer or per-cycle success rate; denominators differ.
Using the result to choose treatment or delay a consultation without discussing time-sensitive factors with a specialist.
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Frequently Asked Questions
Is this a personal prediction of live birth?
No. It is a simplified educational model using broad rates from limited published data. A fertility clinic can provide counseling based on its results and your circumstances.
Which age should I enter?
Enter completed age when the eggs were retrieved and frozen. Current age is not the input used to choose the model’s rate.
Why does the calculator stop at age 40?
The selected evidence bands are kept to ages represented more clearly in the cited estimates. Outcomes at later ages need especially careful clinic-specific counseling rather than extrapolation here.
Does the egg count mean eggs retrieved?
Use the number of mature eggs actually frozen. A retrieval count may include immature eggs or eggs that were not cryopreserved.
Why can clinic estimates differ?
Clinics may use their own laboratory outcomes and models that account for thawing, fertilization and embryo development. They may also report results per cycle or transfer rather than per warmed egg.
Can this decide how many eggs I need?
No. ASRM reports insufficient evidence to prescribe one absolute number for a reasonable chance of birth. Discuss goals, age, likely response, risks and clinic data with a reproductive specialist.