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.
One rule of thumb suggests rebalancing when any portfolio component drifts 5 percentage points from your goal. Daniel De Visé, USA Today, 16 May 2026 Another rule of thumb, Elke says, is that the hatch tends to kick off sooner during drought and low-water years (which would include 2026). Dac Collins, Outdoor Life, 14 May 2026 Miskovich says there's no one-size-fits all number but there are a few common rules of thumb people can use to estimate retirement needs. Derek James, CBS News, 12 May 2026 These days, many medical experts agree that age 40 is the rule of thumb — but their patients don't necessarily know that. Jamie Ducharme, Health, 5 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 20 May. 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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