Sidney
108,987 recorded births · active 1880–2025
Compare Sidney →Living-age distribution
The median living Sidney is 36. If you meet a Sidney, there's about a 70% chance they're between 19 and 74 years old.
Popularity arc
Peak Sidney: 1912. Down 92% from peak.
Projected: the dashed 10-year forecast (Holt damped-trend exponential smoothing, fit to recent years), with a shaded 95% interval.
Gender balance
60.9% male, 39.2% female.
Among males: median age 59 (25–78). Among females: median age 26 (16–35).
Rarity
Sidney ranks #655 out of 105,966 names ever recorded by the SSA.
Geographic fingerprint
Sidneys are 1.3x more common in the South than the national average.
Predictive modeling
Three statistical models, all fit to Sidney's own SSA history plus the historical behavior of every other name in the dataset.
Peak popularity prediction
Sidney's modeled peak was #193 in 1912 — its trend isn't projected to beat that.
Projects the trend forward, then converts share into rank using this year's popularity distribution.
This forecasts Sidney's share of births by fitting a damped-trend model to its last 146 years of data and projecting 10 years forward with a widening uncertainty band. Each projected share is then translated into a rank by comparing it against 2025's actual name-popularity distribution — so the model implicitly assumes the overall shape of that distribution doesn't shift much over the forecast window. Its trend is projected to stay below its historic best over the next 10 years, so the model treats 1912 as its peak. Milestone probabilities come from how much of each year's uncertainty band clears that milestone's rank, combined across years as if they were independent — which slightly overstates the odds for names sitting right at a threshold, since a good year is usually followed by another good year rather than an independent coin flip.Name life-cycle stage
A rule-based classifier over recent growth, momentum, and peak proximity.
Sidney peaked in 1912 and now sits at roughly 8% of that peak, 113 years later — a name that was genuinely common once, now mostly heard from an older generation.
Popularity survival model
Once a name reaches a rank tier, how long does it typically stay there before falling out?
Built from a Kaplan-Meier survival curve: every historical run any name has ever had above this tier, with runs still ongoing today counted as still in progress rather than as an exit.Sidney isn't currently in the Top 100 tier. Estimated chance of entering it in the forecast window: 0%.
If Sidney enters Top 100, chance it's still there after:
Names that do enter Top 100 have historically stayed a median of ~19 years. Based on 668 historical Top 100 runs across every name in the dataset.