Age Calculation Guides

The famous ‘lefties die nine years younger’ finding came from a flawed study design. Here is what the modern cohort data shows about handedness and aging.

Millennials are 30 to 45 in 2026, but the boundary moves depending on which definition you use. Here are the competing date ranges, the ages they produce this year, and how they compare against Gen X and Gen Z.

Identical twins share a birth date but not necessarily a birth minute, and a rare set of cases puts twins in different years. Here is the biology, the exact age math, and the record-keeping rules behind it.

Adults lose 1-3 cm of height between their twenties and seventies, with women losing twice as much as men. Here are the decade averages, the mechanisms, and the measurement traps.

By 60 most adults have lost roughly half their olfactory receptors while taste buds hold up better. Here are the thresholds, the timeline, and the adjustments that actually restore flavour.

Presbycusis starts in the high frequencies in your 30s and 40s, long before conversation gets hard. What changes each decade, why it matters for cognition, and a five-question self-check.

Gait speed is one of the strongest predictors of remaining life expectancy after age 65. Here is what the numbers are, how to measure yours in a hallway, and what the results mean by decade.

A 100-year life is 36,525 days, about 3.15 billion heartbeats, and roughly 175,000 meals. Here is what the numbers actually look like at the century mark.

Your birth date reduces to a single digit using a 1,900-year-old method. Here is the arithmetic, the master-number exceptions, and what each number means.

Vocal folds lose elasticity at about 1% per year after 30. Here is what changes, when, and how to estimate a speaker’s age from recorded voice alone.