Gender probability by name
A gender without a probability is a guess with good posture. Every answer here carries the ratio it was computed from, the number of observations behind that ratio, and a confidence tier derived from both.
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probability is a ratio, not a mood
The probability field is an integer from 50 to 100, and it reports the observed dominant-gender share in the underlying registration data. When it says 84 for Jordan, 84% of the 62,240 recorded people named Jordan were male. It is not a classifier expressing how sure it feels.
That distinction decides how you should use it. A ratio inherits all the weakness of the sample it was computed on, which is why the sample size travels with it in a separate field rather than being folded into a single score.
{
"name": "Jordan",
"gender": "male",
"probability": 84,
"total_names": 62240,
"confidence": "high",
"source": "db"
}
The confidence tiers, and the exact thresholds
confidence is derived mechanically from total_names. There is no judgement between the count and the label, so you can reproduce the tier yourself from the same response.
| Tier | Condition | What it means for you |
|---|---|---|
| high | 100 or more observations | Safe to write to a record, subject to your probability threshold |
| medium | 25 to 99 observations | Usable for addressing, thin for reporting |
| low | 1 to 24 observations | Treat as a hint; review before acting |
| unverified | 0 observations | The source publishes no counts. May be right; is not counted |
| unknown | gender is null | No evidence. Not a female default |
Why a correct answer can still say unverified
Counted registration data comes from seven national statistics offices — the US SSA, the UK ONS, France INSEE, Statistics Canada, Spain INE, Ireland CSO and Statistics Norway. Everywhere else, coverage comes from WGND 2.0, which spans 195 countries and territories and carries no counts at all.
So a Turkish, Italian or Indian name usually returns the right gender with total_names: 0 and confidence: unverified, because those countries do not publish name registration volumes. The label is a statement about auditability, not about correctness. Our measured accuracy in those markets is published on each country page.
Probability from a countless source is capped at 95, so a 100 always means a counted, unanimous sample.
Where to put your threshold
There is no universal cutoff, only a cutoff per use. These are the ones we would defend:
The reporting row is the one people get wrong most often. When you are counting rather than addressing, filling the unresolved rows in with the majority class does not remove the bias — it moves it somewhere you can no longer see it. Names that fail to resolve are not a random sample: they cluster by script and by country, so imputing them systematically inflates whichever group your data already covers best.
Whatever threshold you pick, record it next to the column. A gender field with no note about how it was produced becomes an unquestioned fact within about two years.
| Use | Rule |
|---|---|
| Marketing salutation | confidence high or medium, probability at least 90 |
| Segmentation and reporting | accept everything including unverified; keep null as its own bucket and never impute it |
| Personalisation with a visible cost of being wrong | confidence high, probability at least 95, review queue for the rest |
| Legal, medical or financial consequence | do not infer gender from a name |
Questions
What does a probability of 50 mean?
That the data is split evenly and the name carries no usable signal in the pool that was searched. Pass a country: many names that look ambiguous globally are decisive within one country.
Why is probability capped at 95 for some names?
Because the source supplied no observation counts. Reporting 100 from a source that cannot count would claim a precision the data does not have.
Can I get the raw counts instead of a probability?
total_names carries the sample size on every response, and the /api/countries endpoint returns the per-country registration breakdown for a name.
Is probability calibrated?
It is an observed frequency, not a calibrated model output. On counted data the two are close by construction; on uncounted data the capped 95 is deliberately conservative rather than calibrated.
Related pages
What is actually in the name-to-gender dataset: seven counted national registries, WGND 2.0 for the rest, versioned snapshots and a per-answer source field.
Predict gender from a Turkish name. Dotted and dotless i handling, the genuinely unisex names, and why correct Turkish answers are still marked unverified.
Append a gender column to a customer list, CRM export or lead database, with a confidence field you can filter on and no monthly credit expiry.
Reading the gender field alone discards everything that says whether to believe it. What each response field means and the thresholds behind confidence.
A reproducible benchmark across 4,610 names, 25 countries and nine writing systems. Two scripts return almost nothing, and we publish those numbers too.
Check it against your own list
Every number on this page is reproducible with a free key. If your data breaks it, that is the more interesting result.