aerobicvsaerobicsWhat's the difference?

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

Which to use

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

#22,563
“aerobic” frequency rank
#39,180
“aerobics” frequency rank
61743
confusion score

Side-by-Side Comparison

Feature aerobic aerobics
Definition Living or occurring only in the presence of oxygen e.g. aerobic bacteria. A form of exercise, designed to enhance one's cardiovascular fitness, normally performed to music.

Where the eye mixes aerobic and aerobics

Muted = shared; highlighted = the visual trap. They share 7 letters in sequence.

7 ch
aerobic
8 ch
aerobics

Visual trap between aerobic and aerobics

These two trip readers on the page rather than in the ear: aerobic is /ɛəˈɹəʊ.bɪk/ while aerobics is /əˈɹəʊbɪks/. Spoken aloud the problem disappears. In writing it persists, because they differ by 1 extra letter(s) - “aerobic” sits inside “aerobics”, and the parts of speech differ too (adjective vs noun), which is usually the fastest check. Our composite confusion score for this pair is 61743, derived from the frequency rank of both members and their visual similarity.

aerobic is recorded at frequency rank #22,563, classified as anadj, pronounced /ɛəˈɹəʊ.bɪk/. aerobics is at rank #39,180, tagged as anoun, pronounced /əˈɹəʊbɪks/.

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 61743, this pair ranks #92,473 of 530,003 scored English confusable pairs - among the most confusable pairs.

Orthographic DNA of aerobic vs aerobics

Shared letters: abceior. Private to "aerobic": -. Private to "aerobics": s.

"aerobic" · 7 letters · shape VVCVCVC  ·  "aerobics" · 8 letters · shape VVCVCVCC

Known mistypes of this pair

  • aerobicaeorbic · aerboic · aerobbic · aerobci · aerobicc · aeroibc · aerrobic · areobic
  • aerobicsaeorbics · aerboics · aerobbics · aerobcis · aerobiccs · aerobicss · aerobisc · aeroibcs

Frequently Asked Questions

Can "aerobic" and "aerobics" be used interchangeably?
No - they are not even the same part of speech. "aerobic" is an adjective and "aerobics" a noun, so a sentence built for one is usually ungrammatical with the other.
In ordinary English text, does "aerobic" or "aerobics" show up more?
"aerobic" is the more common of the two: it sits at frequency rank #22,563 in our English list, against #39,180 for "aerobics". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

Eye-level mix-up between "aerobic" and "aerobics" is sorted above. Next: full entries or other pairs that share a letter shape.

  • Full dictionary entry for "aerobic" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "aerobics" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #92,473 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "aerobic" and "aerobics" also get mixed up with nearby pairs, the highest-scored neighbour is "aerobic vs anaerobic". 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 #92,473 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