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.
For many houseplants, allowing the top inch or two of soil to dry out before watering is a good rule of thumb. Alexandra Jones, The Spruce, 11 Apr. 2026 The traditional real estate industry rule of thumb has been that a seller's market is one with less than 4 months of supply of homes to buy, while a buyer's market is 6 months or greater. Andrea Riquier, USA Today, 10 Apr. 2026 The exact spacing varies according to the species and cultivar being grown, but a handy rule of thumb is to set low-growing hedge plants (3-4 feet tall) about two feet apart within rows. Kim Toscano, Southern Living, 9 Apr. 2026 Jon Meador taught us some rules of thumb for grain movement, and another shopmate has a CNC [Computer Numerical Control] machine that’s been helpful to us. Lisa Boone, Los Angeles Times, 8 Apr. 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 19 Apr. 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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