BMI vs by, What's the Difference?

Which to use

“BMI” is a noun and “by” is a preposition - they look or sound alike but fill different roles in a sentence.

#16,419
“BMI” frequency rank: #24
“by” frequency rank: 16443
confusion score

Side-by-Side Comparison

Feature	BMI	by
Definition	Initialism of body mass index.	Near or next to.

Letter map: BMI vs by

Shared letters muted; letters that set BMI and by apart highlighted. Shared run: 1.

3 ch

BMI

2 ch

Grammar separator: BMI vs by

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: BMI is anoun and byapreposition. On the page they differ by 1 letter(s) in length. Our composite confusion score for this pair is 16443, derived from the frequency rank of both members and their visual similarity.

BMI is recorded at frequency rank #16,419, classified as anoun. by is at rank #24, tagged as aprep, pronounced /baɪ/.

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 16443, this pair ranks #457,708 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of BMI vs by

Shared letters: b. Private to "BMI": im. Private to "by": y.

"BMI" · 3 letters · shape CCV · "by" · 2 letters · shape CV

Frequently Asked Questions

Is swapping "BMI" for "by" ever safe?

No - they are not even the same part of speech. "BMI" is a noun and "by" a preposition, so a sentence built for one is usually ungrammatical with the other.

In ordinary English text, does "BMI" or "by" show up more?

"by" is the more common of the two: it sits at frequency rank #24 in our English list, against #16,419 for "BMI". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

What to do next

Done with this confusable. These links stay specific to "BMI" and "by".

Full dictionary entry for "BMI" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "by" - compare definitions side by side with the headword page. Word entry
This pair ranks #457,708 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
"BMI" and "by" also get mixed up with nearby pairs, the highest-scored neighbour is "BFS vs BMI". Nearby pair

Confusion rank #457,708 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.