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Chances of Getting Pregnant Calculator
About you
This is an average estimate for healthy couples with regular cycles — not medical advice and not a prediction for one person.
Example: age 30, 28-day cycle, last period January 1, 2026 — about 20% per cycle, 73.8% within 6 months, 93.1% within 12 months; fertile window January 10–16, 2026.
Behind the numbers
How your chances are estimated
Your chance of conceiving in a single cycle depends mostly on age, because egg quantity and quality fall as you get older. The calculator looks up the average monthly chance for your age band, then works out the chance over several months: if each cycle has a monthly chance p, the chance of conceiving within N months is 1 − (1 − p)^N. It also estimates your fertile window from your last period and cycle length — ovulation is about 14 days before the next period, and the fertile window runs from 5 days before ovulation to the day after it. All of these are averages for healthy couples with regular cycles, not a prediction for one person.
Worked example: age 30 falls in the 30–34 band, so p = 20%. Within 6 months: 1 − 0.80^6 = 1 − 0.262 = 73.8%. Within 12 months: 1 − 0.80^12 = 1 − 0.0687 = 93.1%.
Fertile window: last period January 1, 2026, 28-day cycle — ovulation = January 1 + (28 − 14) days = January 15, 2026; fertile window = January 10 to January 16, 2026.
Rates used
Monthly chance of conception by age
The calculator uses these commonly cited ASRM figures for healthy couples — the average chance of conceiving in a single cycle, by age band:
| Age | Monthly chance |
|---|---|
| Under 25 | 25% |
| 25–29 | 25% |
| 30–34 | 20% |
| 35–39 | 15% |
| 40–44 | 5% |
| 45 and over | Under 1% |
Each band is rounded to a single value so the calculator can use it. For ages 45 and over the calculator uses 1% as its working value. These are population averages, not individual predictions.
Make the most of each cycle
The fertile window is short — aim for intercourse every 1 to 2 days across it, not just on ovulation day.
Track a few cycles first: if your cycle length varies by more than a few days, the ovulation estimate is less reliable.
Age is the biggest factor, but smoking, very low or high weight, and irregular cycles also lower monthly chances.
If you have been trying for 12 months under 35, or 6 months at 35 to 39, talk to a doctor — earlier if your cycles are irregular.
Good to know
Frequently asked questions
What are my chances of getting pregnant at 30?
About 20% in any single cycle, using the age bands on this page. That works out to about 73.8% within 6 months and about 93.1% within 12 months of trying. These are averages for healthy couples — your own chance depends on many factors, including cycle regularity and your partner's fertility.
Does timing in the cycle matter?
Yes. Conception is only possible in the fertile window — roughly the 5 days before ovulation through the day after it — because sperm can live up to 5 days and an egg for about 1 day. Intercourse in that window gives the best chance each cycle; outside it, the chance is close to zero.
How long should I try before seeing a doctor?
General guidance is to seek advice after 12 months of trying if you are under 35, after 6 months if you are 35 to 39, and earlier if you are 40 or older. This is general guidance, not medical advice — if you have irregular cycles or a known health condition, talk to a doctor earlier.
Is this medical advice?
No. This calculator gives an average estimate from published age bands — it cannot account for your cycle, health history, or your partner. A clinician can assess your individual situation.