Word.ws English Dictionary

rule of thumb

rule of thumb noun: a general guideline, rather than a strict rule; an approximate measure or means of reckoning based on experience or common knowledge.

Noun

rule of thumb (plural rules of thumb)

  1. (idiomatic) A general guideline, rather than a strict rule; an approximate measure or means of reckoning based on experience or common knowledge.
    • The usual rule of thumb says that to calculate when an investment will double, divide 70 by the interest rate.
    • Here's a good rule of thumb:
      Too clever is dumb.c. 1935, Ogden Nash, “Reflection on Ingenuity”, in Verses from 1929 On, published 1959
  2. (attributive, usually hyphenated) Approximated, guesstimated.
    • I made a quick, rule-of-thumb estimate of the manhours required for the job.

rule of thumb meaning in Tamil and Arabic

rule of thumb in Tamil

குத்துமதிப்பு விதி

rule of thumb in Arabic

general guideline rather than a strict rule
قَاعِدَة عَامَّة

Forms of rule of thumb

pluralrules of thumb
alternative formrule-of-thumb

Origin of rule of thumb

Attested since 1658. Of uncertain origin, but probably based on the use of the thumb as reference for various measurements. For instance, one theory notes that the inch originated as the distance between the base of the thumbnail and the first joint, another notes the practice of approximating the general direction of the wind by wetting the thumb then raising it in the air. A third theory notes that English royal banquet plate setters used the distance of their thumbs to equally space each plate from the table edge. The erroneous claim that the term referred to the maximum thickness of a stick with which it was permissible for a man to beat his wife has appeared in The Washington Post and Time; it may originate from Del Martin's 1976 book Battered Wives.

Questions about rule of thumb

What does rule of thumb mean?
Rule of thumb means a general guideline, rather than a strict rule; an approximate measure or means of reckoning based on experience or common knowledge.
What is rule of thumb in Tamil?
Rule of thumb in Tamil is குத்துமதிப்பு விதி. See Rule of thumb meaning in Tamil.
What part of speech is rule of thumb?
Rule of thumb is a noun.
What is the plural of rule of thumb?
The plural of rule of thumb is rules of thumb.

Words near rule of thumb in the dictionary

  1. rule of the road
  2. rule of the shorter term
  3. rule of thirds
  4. rule of three
  5. rule of threes
  6. rule of thumb
  7. rule of tincture
  8. rule of two
  9. rule off
  10. rule OK
  11. rule on

Source and license

Adapted from Wiktionary: rule of thumb (page history and authors); rule of thumb (Tamil Wiktionary) (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

Last updated:

Pronunciation audio from Wikimedia Commons, each file under its own free license: En-au-rule of thumb.ogg.

Cite this entry: “rule of thumb.” Word.ws, https://word.ws/rule_of_thumb. Based on Wiktionary, CC BY-SA 4.0.