rule of thumb

noun phrase

1
: a method of procedure based on experience and common sense
2
: a general principle regarded as roughly correct but not intended to be scientifically accurate

Examples of rule of thumb in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Designer Jennie Holland abides by the rule of thumb to use no more than three ‘features’ on the exterior. Cameron Beall, Southern Living, 29 May 2026 By utilizing simple tools such as the 25X rule of thumb and the 4%+ rule of thumb, individuals may be able to back into practical income targets. Wes Moss, Forbes.com, 27 May 2026 But there are rules of thumb that can serve as a general starting point. Greg Iacurci, CNBC, 24 May 2026 The rule of thumb is to stay three bus lengths away from deer and elk and 10 bus lengths from wolves and bears. Maryam Siddiqi, Travel + Leisure, 23 May 2026 See All Example Sentences for rule of thumb

Word History

First Known Use

circa 1658, in the meaning defined at sense 1

Time Traveler
The first known use of rule of thumb was circa 1658

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Cite this Entry

“Rule of thumb.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/rule%20of%20thumb. Accessed 4 Jun. 2026.

Kids Definition

rule of thumb

1
: a method based on experience and common sense
2
: a general principle that is roughly correct
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