Per cent and percent are variants of the word that describes one part of a hundred.
Both spellings, percent and per cent, are acceptable. Percent is more common in US usage; per cent is more common in British usage. The original term was “per centum” which evolved in British English to “per cent.” and finally ended to be written as “per cent”.
- The city’s white population has a 6 percent poverty rate, lower than the white rate in every state. [New York Times]
- Treasury dealers were left holding 62.3 per cent of the $32bn three-year sale. [Financial Times]
And what about “percentage”?
The rule for using per cent and percentage is straightforward. The word percent or per cent (or the symbol %) accompanies a specific number, whereas the more general word percentage is used without a number.
- Fifteen per cent of the control group responded to treatment with Drug A.
- More than 95% of the participants who responded to the survey reported positive results.
- A large percentage of the population has been exposed to rotavirus.
- The percentage of the population exposed to rotavirus is between 70% and 75%.
Are percentages plural or singular?
It depends, if we are referring to a percentage of something, then the object of the preposition determines whether we use a singular or plural verb.
- Forty percent of the chocolate is missing. (In this sentence the chocolate is singular so we use a singular verb.)
- Forty percent of the chocolate chips are missing. (In this sentence the chocolate chips is plural so we use a plural verb.)
What happens when there is no object of the proposition? The object could be implicit in the sentence and explicit in the context. In that case, we will follow the same rule once the object has been identified.
- The chocolate is delicious. Forty per cent is already gone.
To finish, watch out!
- Things can’t decrease by more than 100%. Never write that a price or anything else decreased by 150%. It is not possible.
- The noun percentage requires an adjective to describe its size (eg, “a large percentage”) when it does not refer to specific numbers in the sentence.
- Only write out the number and the word per cent at the beginning of a sentence (eg, “Ten per cent…”). The rest of the time use the number.