known quantity
Meaning
A person or thing whose qualities, behavior, and reliability are already understood; low uncertainty compared with an unfamiliar alternative.
Origin
From mathematics/science and measurement: a “known quantity” is an established value. Figuratively, it came to mean something familiar and predictable versus an unknown variable.
Notes
Often used in comparisons (known quantity vs unknown). Implies safety/predictability; can also hint the option is less exciting than a new one. Common in business, hiring, sports.
Examples
-
We stuck with our current vendor because they’re a known quantity and the service is reliable.
-
He’s a known quantity in this league, so the scouts weren’t surprised by his performance.
-
Hiring an internal candidate felt safer than taking a chance on a known quantity from outside the industry.
-
The new software is cheaper, but our existing system is a known quantity and less risky to maintain.
-
She may not be flashy, but she’s a known quantity who consistently delivers on deadlines.
Grammar & Usage Notes
Usually a noun phrase: “a known quantity” or “the known quantity.” Plural: “known quantities.” Common pattern: “X is a known quantity” and contrast with “an unknown quantity.”
Synonyms
- safe bet
- sure thing
- known entity
- proven performer
Antonyms
- unknown quantity
- wild card
- question mark