Which to use
“ppm” is an abbrev and “Psi” is a noun - they look or sound alike but fill different roles in a sentence.
- #40,761
- “ppm” frequency rank
- #35,967
- “Psi” frequency rank
- 76728
- confusion score
Side-by-Side Comparison
| Feature | ppm | Psi |
|---|---|---|
| Definition | Mengeneinheit/Quotient, die die Konzentration eines Stoffs in einem anderen Stoff angibt; für Englisch parts per million, für Anzahl Teilchen in einer Million Teilchen; 1 ppm = 0,001 ‰ = 0,0001 %; Veranschaulichung: 1 ppm = etwa 5 Wassertropfen (á 0,05 ml) auf eine Badewanne mit Wasser (á 250 l) | Name des dreiundzwanzigsten Buchstabens im griechischen Alphabet |
Where the eye mixes ppm and Psi
Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.
Why the eye confuses ppm with Psi
These two trip readers on the page rather than in the ear: ppm is [peːpeːˈʔɛm] while Psi is [psiː]. Spoken aloud the problem disappears. In writing it persists, because they share most of their letters but differ in 2 positions, and the parts of speech differ too (abbrev vs noun), which is usually the fastest check. Our composite confusion score for this pair is 76728, derived from the frequency rank of both members and their visual similarity.
ppm is recorded at frequency rank #40,761, classified as anabbrev, pronounced [peːpeːˈʔɛm]. Psi is at rank #35,967, tagged as anoun, pronounced [psiː].
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 76728, this pair ranks #277,103 of 2,006,359 scored German confusable pairs - among the most confusable pairs.
Orthographic DNA of ppm vs Psi
Shared letters: p. Private to "ppm": m. Private to "Psi": is.
"ppm" · 3 letters · shape CCC · "Psi" · 3 letters · shape CCV
Frequently Asked Questions
Is swapping "ppm" for "Psi" ever safe?
Which is more common, "ppm" or "Psi"?
Useful next steps
Eye-level mix-up between "ppm" and "Psi" is sorted above. Next: full entries or other pairs that share a letter shape.
- Full dictionary entry for "ppm" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "Psi" - compare definitions side by side with the headword page. Word entry
- This pair ranks #277,103 of 2,006,359 scored German confusable pairs in this corpus vintage. Corpus statistics
- "ppm" and "Psi" also get mixed up with nearby pairs, the highest-scored neighbour is "PMS vs ppm". Nearby pair
Confusion rank #277,103 of 2,006,359 scored German pairs, corpus vintage 2026-09-03, not spelling advice.