Parental Age Gender Probability Calculator
Uses parental age gap statistics to estimate gender likelihood. Visualizes data with a dynamic pie chart.
About
Scientific studies on human sex ratios (secondary sex ratio) have occasionally highlighted correlations between parental age and the likelihood of conceiving a boy or a girl. Some datasets suggest that older fathers are slightly more likely to father sons due to chromosomal viability, while other models focus on the age gap between partners.
This tool references a matrix of 1000 statistical data points (simulated from general demographic trends) to map your specific age combination to a historical probability. It provides a dry, data-driven alternative to folklore methods.
Formulas
The calculator approximates the ratio R (boys : girls) using a logistic function of the age gap Δ:
Ratios are normalized against the natural human baseline of 105 boys per 100 girls.
Reference Data
| Factor | Trend Description | Reference |
|---|---|---|
| Paternal Age > 35 | Slight increase in male births | Demographic Analysis |
| Maternal Age > 35 | Slight increase in female births | Clinical Obs. |
| Age Gap (Father >> Mother) | Higher male probability | Liverpool Univ. Study (Cited) |
| Age Gap (Mother > Father) | Neutral / Slight female bias | General Stats |
| Stress Factors | Stress lowers male ratio | Population Studies |