oldvsozWhich spelling fits?

Quick tell: old is a adjective, oz is a noun, so they fill different roles in a sentence.

Which to use

“old” is an adjective and “oz” is a noun - they look or sound alike but fill different roles in a sentence.

#174
“old” frequency rank
#7,037
“oz” frequency rank
7211
confusion score

Side-by-Side Comparison

Feature old oz
Definition Of an object, concept, relationship, etc., having existed for a relatively long period of time. Abbreviation of ounce; any of various units of weight and volume.

Where the eye mixes old and oz

Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.

3 ch
old
2 ch
oz

Why the eye confuses old with oz

These two trip readers on the page rather than in the ear: old is /ˈəʊld/ while oz is /aʊns/. Spoken aloud the problem disappears. In writing it persists, because they differ by 1 letter(s) in length, and the parts of speech differ too (adjective vs noun), which is usually the fastest check. Our composite confusion score for this pair is 7211, derived from the frequency rank of both members and their visual similarity.

old is recorded at frequency rank #174, classified as anadj, pronounced /ˈəʊld/. oz is at rank #7,037, tagged as anoun, pronounced /aʊns/.

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 7211, this pair ranks #508,091 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of old vs oz

Shared letters: o. Private to "old": dl. Private to "oz": z.

"old" · 3 letters · shape VCC  ·  "oz" · 2 letters · shape VC

Frequently Asked Questions

Do "old" and "oz" mean the same thing in a sentence?
No - they are not even the same part of speech. "old" is an adjective and "oz" a noun, so a sentence built for one is usually ungrammatical with the other.
In ordinary English text, does "old" or "oz" show up more?
"old" is the more common of the two: it sits at frequency rank #174 in our English list, against #7,037 for "oz". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

Useful next steps

Visual near-miss handled. Browse the word pages or a neighbour when the next look-alike shows up.

  • Full dictionary entry for "old" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "oz" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #508,091 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "old" and "oz" also get mixed up with nearby pairs, the highest-scored neighbour is "omi vs oz". Nearby pair

Confusion rank #508,091 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