From Longman Dictionary of Contemporary Englishrule of thumbrule of thumbGUESSa rough figure or method of calculation, based on practical experience As a general rule of thumb, children this age should not spend more than one hour on homework. → rule
Examples from the Corpus
rule of thumb• You should tip bellmen $1- $2 per bag, as a rule of thumb.• As a rule of thumb, funds with durations of one to three years are relatively conservative.• Journalists have a rule of thumb: the more a person knows, the more that person can learn.• It was a place, Wade came to understand, where lost was a rule of thumb.• When constructing a footpath we follow rules of thumb.• A good rule of thumb is to think of 30k as around the upper limit for a page.• Business development professionals often rely on simple rules of thumb to sort potential relationships and weed out unlikely partners.• In general, the rule of thumb was that one's peers were seconded to perform the role.• The rule of thumb no longer mattered. 