installmentvsinstalmentWhat's the difference?

Which to use

“installment” and “instalment” are a confusable English pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#13,369
“installment” frequency rank
#27,513
“instalment” frequency rank
40882
confusion score

Side-by-Side Comparison

Feature installment instalment
Definition One of a series of parts, whether equal or unequal to the other parts of the series, of a given entity or a given process, which part presents or is presented at a particular scheduled interval. Australia, British, and Canada standard spelling of installment.

Where the spellings diverge

Shared letters are muted; the letters that actually set installment and instalment apart are highlighted. They share 10 letters in sequence, which is exactly why the eye skips the difference.

11 ch
installment
10 ch
instalment

Spelling & Dictionary Insight

This is the hard kind. installment and instalment are pronounced identically (/ɪnˈstɔːl.mənt/) and both work as anoun. Neither the ear nor the grammar will rescue you; only the meaning does, so the glosses below are the whole decision. They differ by 1 letter(s) in length. Our composite confusion score for this pair is 40882, derived from the frequency rank of both members and their visual similarity.

installment is recorded at frequency rank #13,369, classified as anoun, pronounced /ɪnˈstɔːl.mənt/. instalment is at rank #27,513, tagged as anoun, pronounced /ɪnˈstɔːlmənt/.

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 40882, this pair ranks #263,566 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of installment vs instalment

Shared letters: aeilmnst. Private to "installment": -. Private to "instalment": -.

"installment" · 11 letters · shape VCCCVCCCVCC  ·  "instalment" · 10 letters · shape VCCCVCCVCC

Known mistypes of this pair

  • installmentinnstallment · insatllment · insstallment · installemnt · installmennt · installmentt · installmetn · installmment
  • instalmentinnstalment · insatlment · insstalment · instalemnt · instalmennt · instalmentt · instalmetn · instalmment

Frequency comparison

installment#13,369
instalment#27,513

Source: FrequencyWords open word-frequency list

Frequently Asked Questions

Can "installment" and "instalment" be used interchangeably?
No. They are pronounced the same (/ɪnˈstɔːl.mənt/), which is exactly why they get swapped in writing, but the dictionary meanings above are different, and pronunciation is no guide here.
Which is more common, "installment" or "instalment"?
"installment" is the more common of the two: it sits at frequency rank #13,369 in our English list, against #27,513 for "instalment". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Remembering installment vs instalment

The fastest way to pick the right one every time.

  • Read both glosses above and match the meaning you intend, only context separates this pair.
  • See each word in full, definition, IPA, etymology and its other confusables. Full “installment” entry
  • Browse more pairs most likely to be confused. Most confusable

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

Source: FrequencyWords open word-frequency list