An example of a rule of thumb is the general guideline that you don't wear white after Labor Day.
rule of thumb
- a rule based on experience or practice rather than on scientific knowledge
- any method of estimating that is practical though not precise
Origin of rule of thumbfrom the method of measuring by the thumb
rule of thumb
nounpl. rules of thumb
Origin of rule of thumbFrom the use of the thumb as a makeshift ruler or measuring device, as in carpentry.
(plural rules of thumb)
- A general guideline, rather than a strict rule; an approximate measure or means of reckoning based on experience or common knowledge.
- The usual rule of thumb says that to calculate when an investment will double, divide 70 by the interest rate.
- (usually hyphenated) Approximated, guesstimated.
- I made a quick, rule-of-thumb estimate of the manhours required for the job.
Michael Quinion lists the first documented use as 1692 while The Oxford English Dictionary puts the first documented use at 1685. Some suggested origins include the fact that the inch originated as the distance between the base of the thumbnail and the first joint, the practice of approximating the general direction of the wind by wetting the thumb then raising it in the air, and the rule of English Royal banquet plate setters using the distance of the thumb to equally space each plate from the table edge. Apocryphally, it has been claimed the term originally referred to the maximum thickness of a stick with which it was permissible for a man to beat his wife, but the earliest use in direct reference to domestic violence may be Del Martin's 1976 book Battered Wives.
- Alternative form of rule of thumb.
rule of thumb - Computer Definition
A rule, or guideline, based on experience and sound judgement rather than scientific knowledge.The origin of the term is vague, but some suggest that it originated in the practice of carpenters, seamstresses, artists, and other craftsmen of using their thumb to approximate measurements.The fact that the measurement of an inch is based on the distance between the thumbnail and the first joint certainly lends credence to this theory.