How NUI is calculated

The Name Universality Index (NUI) is a 0–100 score. It is the weighted average of four axes, computed for each of 65 languages and then averaged worldwide.

Pronunciation — 30%

Each language has expected letter combinations and awkward ones. We score how naturally a name flows in that language's phonology — rewarding natural digraphs, penalizing hard consonant clusters, forbidden letters, and excessive length.

Meaning safety — 35%

We check the name against a curated list of vulgar, taboo, or otherwise unsuitable words per language, blended from the open LDNOOBW dataset and a small set of hand-curated cultural flags. Exact matches weigh most heavily.

Cultural fit — 20%

Religious, regional, or cultural conflicts are flagged. Languages whose cultures favor shorter names apply a gentle length penalty.

Script support — 15%

Whether the name can be naturally written in the language's script — Latin, Cyrillic, Arabic, Devanagari, Hangul, Hiragana, or Hanzi. Names in non-native scripts get a best-effort transliteration preview.

Notes & limitations

Worked example: scoring "Sofia"

Take the name Sofia. Its global NUI is 95 (grade S) — it travels almost everywhere. In English it scores 97 (pronunciation 100, meaning 100, cultural fit 85, script 100): two open syllables, no awkward consonant clusters, no taboo collisions, and it writes cleanly in the Latin alphabet. It stays high in scripts it isn't native to — Japanese 94, Arabic 94, Chinese 91 — because it transliterates into each one without losing its shape. A name with hard consonant clusters or a meaning clash in some language would lose points on those axes and pull the worldwide average down.

Glossary

NUI (Name Universality Index)
A 0–100 score for how well a name works across 65 languages — the weighted average of the four axes.
Axis
One of the four dimensions scored per language: pronunciation, meaning safety, cultural fit, and script support.
Phonology
The sound system of a language — which letter combinations are natural to pronounce and which feel foreign.
Digraph
A pair of letters that represent one sound (such as "sh" or "th"). Natural digraphs help a name's pronunciation score; awkward ones hurt it.
Transliteration
Rewriting a name in another script (for example Latin "Sofia" → Japanese "ソフィア") so readers of that script can pronounce it.
Grade
A letter (S, A, B, C, D, F) summarizing the NUI band, for a quick read at a glance.

Frequently asked questions

How is the NUI calculated?

NUI is a 0–100 score: the weighted average of four axes — Pronunciation (30%), Meaning safety (35%), Cultural fit (20%) and Script support (15%) — computed for each of 65 languages and then averaged worldwide. It is rule-based, runs in your browser, and uses no AI.

What does the Pronunciation score mean?

It scores how naturally a name flows in each language's phonology — rewarding natural letter combinations and penalizing hard consonant clusters, forbidden letters and excessive length.

How is Meaning safety checked?

The name is checked against a curated list of vulgar, taboo or unsuitable words per language, blended from the open LDNOOBW dataset plus hand-curated cultural flags. Exact matches weigh most heavily.

What is Cultural fit?

Religious, regional or cultural conflicts are flagged, and languages whose cultures favor shorter names apply a gentle length penalty.

What is Script support?

Whether the name can be naturally written in the language's script — Latin, Cyrillic, Arabic, Devanagari, Hangul, Hiragana or Hanzi — with a best-effort transliteration preview for non-native scripts.

What if a name is fine in one language but offensive in another?

Each language is scored independently, so a name can score high in most languages and low in a few. The global NUI is the average, and the per-language breakdown shows exactly where a name stumbles.

Can a name's score change over time?

Scores are deterministic for a given version of the rules. We refine the language data and word lists over time, so a score can shift slightly as the methodology improves.

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