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

Traders use a rule of thumb that 16 points for the VIX equate to a 1% move in the index. — Oliver Renick, CNBC, 5 Nov. 2026

The first rule of thumb—and a solid piece of advice to live by—is that looks can be deceiving. — Jennifer Hussein, Allure, 1 Nov. 2026

Celebrity hairstylist Mike Martinez’s rule of thumb for the perfect clean? — Valeriya Chupinina, Vogue, 20 Oct. 2026

The rule of thumb for warm-season grasses is not to fertilize them later than 4-6 weeks before the first frost; a nutrient boost too late in the season would interfere with their winter dormancy. — Nadia Hassani, The Spruce, 13 Oct. 2026

Word History

First Known Use

circa 1658, in the meaning defined at sense 1

Rhymes for rule of thumb

• abomasum
• become
• checksum
• humdrum
• income
• outcome
• pisum
• succumb
• therefrom
• wherefrom
• bum
• chum

Kids Definition

rule of thumb

1

: a method based on experience and common sense

2

: a general principle that is roughly correct