Estimate by age
Fertility by age band — comparison
Monthly fecundity rate (MFR), chance of conceiving within 12 cycles, median cycles to conceive, and IVF live-birth per cycle (own eggs, at the band’s midpoint age). Population averages.
| Age band | Monthly chance | Within 12 months | Median cycles | IVF / cycle* |
|---|---|---|---|---|
| 18–24 | 20–25% (22.5%) | 95.3052% | ≈2.7 | ≈40% |
| 25–29 | 20% | 93.1281% | ≈3.1 | ≈40% |
| 30–34 | 15% | 85.7758% | ≈4.3 | ≈40% |
| 35–39 | 10% | 71.757% | ≈6.6 | ≈30% |
| 40–44 | 5% | 45.964% | ≈13.5 | ≈10% |
| 45–55 | ~1% | 11.3615% | ≈69 | ≈5% |
*IVF live-birth per cycle started, own eggs, at the band midpoint age. Ranges: under 35 ~35–45%, 35–37 ~25–30%, 38–40 ~18–22%, 41–42 ~10–12%, over 42 ~4–5% (SART/CDC/HFEA national reports).
IVF success by age
Live-birth rate per IVF cycle started, using your own eggs (rounded national averages from SART/CDC/HFEA). Rates vary widely by clinic, protocol, diagnosis, and embryo quality.
Male age factor
Age affects male fertility too, but modestly and gradually compared with the sharper female age curve:
- Time to pregnancy lengthens slightly when the male partner is over 40.
- Small absolute increases in miscarriage risk and certain de novo genetic conditions are reported at older paternal ages.
- Semen parameters (count, motility, morphology) decline gradually; there is no sharp cutoff equivalent to the female mid-30s decline.
- The evidence base is smaller and less consistent than for maternal age — this tool does not apply a numeric male-age adjustment for that reason.
Both partners’ ages are worth discussing with a fertility specialist.
Methodology & sources
- Monthly fecundity rate (MFR): probability of conceiving in one menstrual cycle. Bands: 18–24 ~20–25%, 25–29 ~20%, 30–34 ~15%, 35–39 ~10%, 40–44 ~5%, 45+ ~1%. Sources: ASRM “Age and Fertility” booklet, ACOG Committee Opinion on Female Age-Related Fertility Decline, British Fertility Society.
- 12-month chance: 1 − (1 − MFR)12 — assumes a constant monthly rate and independent cycles (a simplification).
- Median cycles to conceive: ln(0.5) / ln(1 − MFR).
- IVF live birth per cycle (own eggs): rounded national averages: under 35 ~40%, 35–37 ~30%, 38–40 ~20%, 41–42 ~10%, over 42 ~5% (SART, CDC ART, and HFEA national reports). Per cycle started; vary by clinic and protocol.
- Age bands: MFR bands are 18–24, 25–29, 30–34, 35–39, 40–44, 45–55 (age 24 → first band, 25 → second, and so on). IVF bands: under 35, 35–37, 38–40, 41–42, over 42 (age 42 → 41–42 band; age 43 → over-42 band).
- Worked anchors verified by independent recomputation: age 33 (MFR 0.15) → 1 − 0.8512 ≈ 85.8% → ~86%; age 35 (MFR 0.10) → ~71.8% → ~72%; age 40 (MFR 0.05) → ~46.0% → ~46%.
Frequently asked questions
What is the monthly chance of getting pregnant at my age?
Doctors call this the monthly fecundity rate: the probability of conceiving in one menstrual cycle. Population averages are roughly 20-25% per cycle at ages 18-24, about 20% at 25-29, 15% at 30-34, 10% at 35-39, 5% at 40-44, and around 1% at 45 and older (sources: ASRM, ACOG, British Fertility Society). These are averages across many women, not a prediction about you.
How is the 12-month chance calculated?
It uses 1 minus (1 minus MFR) to the power of 12, where MFR is the monthly fecundity rate. For example, at age 33 the monthly rate is about 0.15, so the 12-cycle estimate is 1 - 0.85^12 = 0.858, about 86%. This assumes the monthly rate stays constant and each cycle is independent, which is a simplification. Real chances vary with cycle regularity, timing, and individual health factors.
What are IVF success rates by age?
Using your own eggs, rounded national averages for live birth per IVF cycle started are about 40% under age 35, 30% at 35-37, 20% at 38-40, 10% at 41-42, and 5% over 42 (SART, CDC, and HFEA national reports). Rates vary widely by clinic, protocol, diagnosis, and embryo quality, so treat these as ballpark figures only.
Does the man's age matter for fertility?
Yes, but less than the woman's age. Paternal age over 40 is linked to a slightly longer time to pregnancy and small absolute increases in miscarriage risk and certain de novo genetic conditions. The decline is modest and gradual compared with the sharper female age curve, and the evidence base is smaller. Both partners' ages are worth discussing with a clinician.
When should I see a fertility specialist?
Standard guidance (ASRM) is: after 12 months of regular unprotected intercourse without conceiving if the female partner is 35 or younger, after 6 months if she is 36-40, and promptly if she is over 40 or has a known risk factor such as irregular cycles, endometriosis, or prior pelvic surgery. Earlier evaluation is reasonable whenever you are concerned.
Do these estimates apply to donor eggs?
No. With donor eggs, success depends mainly on the donor's age, not the recipient's. National data show live-birth rates around 50% per cycle with donated eggs, with little effect of the recipient's age. The IVF tab of this tool covers own-egg cycles only.
Why might my own experience differ from these numbers?
Because these are population averages. Your individual chance depends on ovulation regularity, fallopian tube and uterine health, sperm factors, cycle timing, weight, smoking, and medical history. Two women of the same age can have very different fertility. This calculator is an educational estimate, never a personal prediction or diagnosis.
Can I improve my monthly chance of conceiving?
General evidence-based steps include having intercourse every 2-3 days across the fertile window, tracking ovulation, maintaining a healthy weight, avoiding smoking and heavy alcohol use, and reviewing medications with a clinician. None of this replaces personalized medical advice: a fertility specialist or OB-GYN can assess your individual situation.
Worked example: what does the calculator show at age 35?
At 35 you fall in the 35-39 band with a monthly fecundity rate of about 0.10. The 12-cycle estimate is 1 - 0.9^12 = 0.718, about 72%. The median time to conceive is about 6.6 cycles. IVF with your own eggs at 35-37 averages about 30% live birth per cycle started. Again: population estimates, not a personal prediction.