thirteenvsthirtiesWhich spelling fits?

Quick tell: thirteen is a num, thirties is a noun, so they fill different roles in a sentence.

Which to use

“thirteen” is a num and “thirties” is a noun - they look or sound alike but fill different roles in a sentence.

#8,494
“thirteen” frequency rank
#21,384
“thirties” frequency rank
29878
confusion score

Side-by-Side Comparison

Feature thirteen thirties
Definition The cardinal number occurring after twelve and before fourteen: ten and three. The fourth decade of a century: the 1830s, 1930s, 2030s, etc.

Letter map: thirteen vs thirties

Shared letters muted; letters that set thirteen and thirties apart highlighted. Shared run: 6. thirteen and thirties follow the identical consonant-vowel pattern (CCVCCVVC). Same shape at a glance is often the real trap, independent of shared letters.

8 ch
thirteen
8 ch
thirties

Grammar separator: thirteen vs thirties

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: thirteen is anum and thirtiesanoun. On the page they share most of their letters but differ in 2 positions. Our composite confusion score for this pair is 29878, derived from the frequency rank of both members and their visual similarity.

thirteen is recorded at frequency rank #8,494, classified as anum, pronounced /ˌθɜːˈtiːn/. thirties is at rank #21,384, tagged as anoun.

Glosses for this pair are partially populated in our dataset, but the full side-by-side definitions above should still guide you to the right choice.

With a confusion score of 29878, this pair ranks #359,277 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of thirteen vs thirties

Shared letters: ehirt. Private to "thirteen": n. Private to "thirties": s.

"thirteen" · 8 letters · shape CCVCCVVC  ·  "thirties" · 8 letters · shape CCVCCVVC

Known mistypes of this pair

  • thirteen ← htirteen · thhirteen · thireten · thirrteen · thirteenn · thirten · thirtene · thirtteen
  • thirties ← htirties · thhirties · thirites · thirrties · thirteis · thirtiess · thirtise · thirtties

Frequently Asked Questions

Can "thirteen" and "thirties" be used interchangeably?
No - they are not even the same part of speech. "thirteen" is a num and "thirties" a noun, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "thirteen" or "thirties"?
"thirteen" is the more common of the two: it sits at frequency rank #8,494 in our English list, against #21,384 for "thirties". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

Done with this confusable. These links stay specific to "thirteen" and "thirties".

  • Full dictionary entry for "thirteen" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "thirties" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #359,277 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "thirteen" and "thirties" also get mixed up with nearby pairs, the highest-scored neighbour is "thirteen vs thirteenth". Nearby pair
  • Recorded mistypes exist for at least one side of this pair, useful when a spell-checker or OCR lands on the wrong form. See mistypes

Confusion rank #359,277 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list