Converter or Convertor: Which Is Correct?

Updated 2026-10-12 · Which One Is Correct editorial team

Quick answer: Both converter and convertor are accepted spellings for the word in question, yet converter is the standard and much more common choice. While the convertor variant exists, it is considered a rare form that you should avoid unless you have a specific reason to use it. This guide clarifies which version you should pick for your writing to ensure clarity and adherence to standard English conventions.

The Short Answer

Both converter and convertor are accepted spellings, but converter is the standard and much more common choice. The convertor variant is a rare form that is generally avoided in modern writing.

People often confuse these words because they sound identical and share the same root. The confusion stems from the fact that the suffix can sometimes appear in different forms depending on the specific word being modified, leading to unnecessary doubt about which spelling is proper.

Side-by-Side Comparison

Form	Status	Use it when
converter	Standard	In almost all general contexts regarding transformation or power supply.
convertor	Rare	Only if adhering to a specific, older technical style guide that mandates it.
noun	Both	When referring to a device that changes energy, currency, or format.
verb-related	None	Neither form is used as a verb; the verb is simply to convert.

Correct Example Sentences

A power converter changes voltage levels for electronic devices.
The currency converter helped me calculate the exchange rate.
This device acts as a signal converter for the home theater system.
Please use the online converter to switch your file format.
The heat converter regulates temperature in the industrial machine.
A language converter translates text from one script to another.
This adapter serves as a plug converter for international travel.
The digital converter processes analog audio into digital signals.
Our software includes a built-in text converter for formatting documents.
The energy converter transforms solar light into usable electricity.

Common Mistakes and Fixes

I used a convertor to change the battery voltage.: I used a converter to change the battery voltage.
Please check the convertor settings before plugging it in.: Please check the converter settings before plugging it in.
The convertor failed to convert the video file correctly.: The converter failed to convert the video file correctly.
He bought a new convertor for his laptop charger.: He bought a new converter for his laptop charger.
This convertor is too expensive for what it does.: This converter is too expensive for what it does.
The convertor on the shelf looks different from the others.: The converter on the shelf looks different from the others.

Related Word Pairs

adhesive vs adhesive: spelling is identical so no confusion exists
accept vs except: accept means agree while except means exclude
affect vs effect: affect is usually a verb and effect is usually a noun
complement vs compliment: complement completes something while compliment praises it
historic vs historical: historic marks importance while historical marks time period
principal vs principle: principal is the leader and principle is a rule
their vs there vs theyre: their shows possession there shows place and theyre is a mistake
less versus fewer: less uses with mass nouns and fewer uses with count nouns

Frequently Asked Questions

Is convertor ever correct to use?

Yes, convertor is technically accepted in some dictionaries, but it is a rare variant. You should almost always choose converter instead because it is the standard spelling and is recognized by the vast majority of users and style guides.

Why do some people still use convertor?

Some people use convertor due to historical habits or specific regional preferences that have faded over time. Occasionally, older technical manuals or specific industry jargon might prefer the variant, but modern general English strongly favors the standard spelling.

Does the choice change the meaning of the word?

No, the choice between these spellings does not change the meaning of the word at all. Both versions refer to the exact same device or action, so the only difference between them is stylistic rather than semantic or functional.

Which spelling should I use for business writing?

For business writing, you should always use the standard spelling, which is converter. Using the rare variant convertor might make your document look outdated or unprofessional, so sticking to the common form ensures your message is clear and professional.