I was going to add an explanatory paragraph here, but then I didn’t.
| Language | Riddle’s Name | Lev.Δ | J-W.Δ | ‘Voldemort’ Anagram |
| English | Tom Marvolo Riddle | 0 | 0.000 | I am Lord Voldemort |
| Estonian | Tom Marvolon Riddle | 1 | 0.018 | Mina Lord Voldemort |
| Turkish | Tom Marvoldo Riddle | 1 | 0.064 | Adim Lord Voldemort |
| Slovakian | Tom Marvoloso Riddle | 2 | 0.033 | A som i Lord Voldemort |
| Portuguese | Tom Servolo Riddle | 2 | 0.074 | Eis Lord Voldemort |
| Russian | Tom Narvolo Reddl | 3 | 0.088 | Lord Volan-de-mort |
| Basque* | Tom Narivoloz Riddle | 3 | 0.137 | Lord Voldemort naiz |
| Spanish | Tom Sorvolo Ryddle | 3 | 0.167 | Soy Lord Voldemort |
| German | Tom Vorlost Riddle | 5 | 0.105 | Ist Lord Voldemort |
| Czech | Tom Rojvol Raddle | 5 | 0.109 | Já Lord Voldemort |
| Ukranian | Tom Yarvolod Redl | 5 | 0.119 | Ya Lord Voldemort |
| Italian | Tom Orvoloson Riddle | 5 | 0.156 | Son io Lord Voldemort |
| Latin | Tom Musvox Ruddle | 5 | 0.248 | Sum Dux Voldemort |
| Bulgarian | Tom Mersvoluko Riddŭl | 6 | 0.116 | Tuk sŭm i Lord Voldemor |
| Hebrew | Tom Vandrolo Ridl | 6 | 0.161 | Ani Lord Voldmort |
| Catalan | Tod Morvosc Rodlel | 7 | 0.291 | Sóc Lord Voldemort |
| Serbian | Tom Mervolodomos Ridl | 8 | 0.158 | To smo mi Lord Voldemor |
| Romanian | Tom Ruvel Doodler | 9 | 0.184 | Eu Lord Voldemort |
| Belarusian | Tom Val’Dor Redl | 9 | 0.199 | Lord Val’Demort |
| Lithuanian† | Tomas Malvoras Ridlis | 9 | 0.206 | Aš Valdovas Voldemortas |
| Swedish | Tom Gus Mervolo Dolder | 10 | 0.232 | Ego sum Lord Voldemort |
| Norwegian | Tom Dredolo Venster | 10 | 0.249 | Voldemort den Store |
| Hungarian | Tom Rowle Denem | 10 | 0.259 | Nevem Voldemort |
| Faroese | Tom Evildo Reger | 10 | 0.270 | Eg eri Voldemort |
| French | Tom Elvis Jedusor | 12 | 0.306 | Je suis Voldemort |
| Finnish | Tom Lomen Valedro | 13 | 0.206 | Ma olen Voldemort |
| Esperanto | Tom Vlades Mistero | 13 | 0.267 | Mi estas Voldemort |
| Icelandic‡ | Trevor Delgome | 14 | 0.307 | Eg er Voldemort |
| Dutch | Marten Asmodom Vilijn | 15 | 0.361 | Mijn naam is Voldemort |
| Slovenian§ | Mark Neelstin | 15 | 0.485 | Mrlakenstein |
| Danish | Romeo G Detlev Jr | 16 | 0.414 | Jeg er Voldemort |
* Good try, Basque, but there are too many Is in NARIVOLOZ
† Some sources have LORDAS instead of VALDOVAS. This isn’t an anagram either way (count the Ms, or Is).
‡ If you know what Neville’s toad was named in Iceland, let me know.
§ Well the anagram is as elegant as any, Slovenia, but changing “Voldemort” and “Tom Riddle” is somewhat cheating.
Ok, so, why is is that the Romance and Slavic language versions generally just run with an embellished middle name, but the Scandinavian language versions are so tortured? “Riddle” is a Germanic word, so it seems weird that none of them opted to keep it, or a cognate.
My guess is the J-G of the first person pronoun is just really hard to work into a proper name (especially, perhaps, with a V already called for). The Swedish translator cleverly opted to put the reveal into Latin, the Norwegian phrase breaks the form completely, the Danish translator managed to get “Jeg er” in there, but at the cost of making Voldemort’s birth name “Romeo G[åde] Detlev, Jr”.
He-Who-Must-Not-Be-Named indeed.