A risky action that has been carefully considered beforehand, in which the chance or likelihood of a beneficial outcome outweighs the risk or cost of failure. We decided to take the calculated risk of going to trial, rather than settling out of court.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
A chance taken after careful estimation of the probable outcome, as in Taking their dispute to arbitration was definitely a calculated risk. This term uses calculated in the sense of "planned with forethought," a usage from the mid-1800s. Its pairing with risk dates from World War II, when the chances for losing bombers were taken into account before a bombing mission was sent out. After the war the term was transferred to other undertakings where taking a chance to succeed had to be weighed against the costs of failure.
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
An action taken even though it might fail, because not taking it might be more dangerous. The term comes from World War II, where it was applied to the chances of losing bombers, personnel and equipment, weighed against the benefits of hurting the enemy. It soon was transferred to other situations. For example, “‘You don’t know a thing about him.’—‘It’s a calculated risk’” (Robert A. Heinlin, Double Star, 1956), or “We took the calculated risk of . . . using inanimate mother surrogates rather than real mothers” (Science, Aug. 21, 1959).
The Dictionary of Clichés by Christine Ammer Copyright © 2013 by Christine Ammer