# Fertility by Age Calculator

URL: https://speedycalculator.com/calculators/health/fertility-by-age/
Last updated: 2026-10-30

> The fertility by age calculator estimates a woman's chance of getting pregnant each cycle and within a year at her age, and the chance of conceiving within the number of months you choose.

## Inputs

- Age (years)
- Months of trying

## Results

- Chance of conceiving each cycle
- Chance within your chosen months
- Chance within one year
- When to seek advice

## Formula

```
Chance per cycle: 25% (19–25), 20% (26–29), 15% (30–34), 10% (35–39), 5% (40–44), 1% (45–49)
Chance within n cycles = 1 − (1 − p)ⁿ
```

## Explanation

Female fertility declines gradually from the late 20s and more steeply after 35, mainly because the number and quality of eggs fall. Most couples under 35 conceive within a year of regular unprotected sex; specialists recommend seeing a doctor after 12 months of trying (6 months over 35).

### How to use the Fertility by Age Calculator

- **Age**
- **Months of trying**

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Choose your age and how many months you plan to try. The figures assume regular unprotected sex in healthy couples; individual fertility varies a lot.

### Inputs explained

FieldWhat to enterAgeIn yearsMonths of tryingA number

### What each result means

- **Chance within your chosen months** = (1 - (1 - [Chance of conceiving each cycle]÷100)^[Months of trying])×100
- **Chance within one year** = (1 - (1 - [Chance of conceiving each cycle]÷100)^12)×100

### Example values

How the main result changes when **Age** changes and everything else stays at the example values above:

Age (years)Chance of conceiving each cycle (%)24253215405481
*Health note: this calculator is for education and screening only and is not a diagnosis or treatment advice. Discuss your results with a qualified clinician.*

## Worked example

Inputs — Age: 32 years; Months of trying: 12.

Results — **Chance of conceiving each cycle = 15 %**; Chance within your chosen months = 86 %; Chance within one year = 86 %; When to seek advice = After 12 months of trying.

## Key terms

- **Fecundability**: The probability of conceiving in one menstrual cycle.

## FAQ

**At what age does fertility decline?**
Gradually from about 30, and faster after 35.

**Does male age matter?**
Yes, sperm quality declines too, especially after about 40–45.

**Can I preserve fertility?**
Egg freezing before 35 gives the best chance; it is not a guarantee.


## Sources

- [ACOG Committee Opinion 589 – Female age-related fertility decline](https://www.acog.org/clinical/clinical-guidance/committee-opinion/articles/2014/03/female-age-related-fertility-decline)
- [NHS – Infertility](https://www.nhs.uk/conditions/infertility/)