On Average vs. In Average – Which is Correct?
The correct phrase is on average. The phrase in average is grammatically incorrect and is not used in standard English to express a typical or mean value. Always use “on average” to refer to a general rule or a calculated mean.
On Average or In Average – Which is Correct?
The distinction between “on average” and “in average” is straightforward: only “on average” is correct in standard English. The phrase “in average” is a common error stemming from confusion over prepositional usage. “On average” functions as an adverbial phrase, meaning “typically,” “generally,” or “based on a calculated mean.” It refers to a state or condition, similar to other idiomatic phrases like “on time” or “on schedule.” “In average” lacks this established idiomatic meaning and is therefore considered incorrect.
The Best Trick to Remember the Difference
A powerful trick to remember the correct phrase is to associate “on” with a general state or a position on a scale. Think of other correct phrases like “on the whole,” “on target,” or “on track.” These all imply a general condition or a relationship to a standard. If you want to convey typicality or a mean value, you are referring to a general state or position, which aligns perfectly with the preposition “on.”
| Word/Phrase | Part of Speech | Meaning | Example |
|---|---|---|---|
| on average | Adverbial phrase | Typically; usually; based on a calculation of the mean. | “On average, the new policy has improved efficiency by 15%.” |
| in average | Incorrect usage | N/A | “In average, sales are higher in June.” (Incorrect) |
How to Use On Average
“On average” is an adverbial phrase used to indicate what is typical or what holds true when considering a set of data or a general trend. It often implies a statistical mean, but can also be used more broadly to mean “usually” or “typically.” This phrase is highly versatile and is used in both formal and informal contexts across various fields, including science, business, and everyday conversation.
Example 1: “The company delivers packages within three business days on average.”
Example 2: “On average, adults need about seven to nine hours of sleep per night.”
Example 3: “Student attendance has been consistent, with 90% present on average each week.”
Etymology of the word On Average
The word “average” itself has an interesting history, stemming from the Old French word “avarie,” which referred to damage to goods or losses at sea. This term evolved through maritime law to describe the proportional distribution of such losses among the ship’s owners and cargo owners. By the 18th century, “average” began to be used in its modern statistical sense, referring to a mean value. The preposition “on” in “on average” signifies a state or condition, much like “on schedule” or “on time,” indicating that something holds true or is typically found within that general state or condition.
Related Concepts
Understanding broader grammatical concepts like prepositions and idioms helps clarify why “on average” is correct and “in average” is not.
- Prepositions: Prepositions like “on,” “in,” “at,” and “for” are small words that connect nouns or pronouns to other words in a sentence, showing relationships of place, time, direction, or manner. Often, the choice of preposition in English is idiomatic, meaning it follows established patterns of usage rather than strict logical rules.
- Idioms: An idiom is a phrase or expression whose meaning cannot be understood from the ordinary meanings of its words. “On average” is an established idiom in English that conveys a specific meaning (typically, generally, as a mean) that is not necessarily derivable by analyzing “on” and “average” separately in a literal sense.
Examples from Media and Literature
- “Global temperatures have risen by approximately 1.5 degrees Celsius on average since the pre-industrial era.” – News Report, June 2026
- “She found that, on average, people tend to overestimate their own abilities.” – Psychology Today article
- “The author typically writes a novel every two years on average, a remarkable pace.” – Literary Review
- “For the upcoming summer, meteorologists predict warmer-than-usual temperatures on average across the continent.” – Weather Forecast, June 2026
On Average Synonyms
| Synonym | Definition |
|---|---|
| Typically | In a typical manner; usually. |
| Generally | In most cases; usually. |
| Normally | Under normal circumstances; usually. |
| Usually | On most occasions; habitually. |
| Routinely | According to a regular procedure; regularly. |
Frequently Asked Questions
Question 1: Why is “on average” correct and “in average” not?
“On average” is the established and correct idiomatic phrase in English to mean “typically” or “as a general rule.” English prepositions often combine with nouns to form fixed expressions. “In average” is not an accepted idiom and does not convey the same meaning.
Question 2: Can “on average” be used at the beginning of a sentence?
Yes, “on average” can be used effectively at the beginning of a sentence to introduce a general statement or a statistical summary. For example: “On average, the project takes six months to complete.”
Question 3: Is there ever a context where “in average” might be correct?
No, “in average” is not standard English for expressing a mean or typical value. While “average” can be used as a noun (e.g., “The team’s performance was below average”), the preposition “in” does not form a correct adverbial phrase with it in this context.
Conclusion
When discussing typical values, general trends, or statistical means, the correct and universally accepted phrase is “on average.” The alternative, “in average,” is grammatically incorrect and should be avoided in all forms of communication. Mastering such common idioms is crucial for clear and professional writing. Pro Tip: Always prioritize precision in your language; using the correct idiom like “on average” enhances your credibility and ensures your message is understood exactly as intended.
