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

Her rule of thumb is to choose cotton, which is breathable and wicks moisture away from the skin, while synthetics like polyester tend to trap heat and sweat against it—creating warm, damp conditions that encourage the growth of yeast and bacteria. — Angela Haupt, Time, 7 July 2026

Costs of nail services vary, but 15 to 20 percent is a good rule of thumb. — Kaitlyn Yarborough, Southern Living, 5 July 2026

The rule of thumb is to read the room and set your volume accordingly. — Jessica Kozuka, Travel + Leisure, 4 July 2026

Stages will generally finish around 5pm (11am) local time, though take that as a very loose rule of thumb — especially with the speed of the modern peloton. — Jacob Whitehead, New York Times, 1 July 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