Donna Perugini Children's Author

Where Did ‘Rule of Thumb’ Have Its Origin


Thumb by Krissen

Attribute Krissen @Flickr


Where do you think the phrase, ‘Rule of Thumb’ came from? 

There are two thoughts here. 

Brewmasters of old often tested the temperature of a batch of beer by dipping a thumb in the brew.  Their long experience told them how well the beer was brewing.  (I wonder if they were thumbsuckers as children?) One theory has it that our expression for a rough, guesswork estimate derives from this practice.  My choice of brew is ice tea, hold the lemon and sugar.


Last Joint of the Thumb

More likely it stems from the ancient use of the last joint of the thumb as a measuring device for roughly one inch.  I measured mine and it’s 1 1/4″.   Have we grown longer thumbs throughout the generations? 

Let me know if your thumb at the last joint to the tip is 1 inch or is it longer.  And if you’re a brewmaster….how’s that thumb working out for you?

taken from the Henry Holt Encyclopedia of Word and Phrase Origins by Robert Hendrickson

8 Responses to “Where Did ‘Rule of Thumb’ Have Its Origin”

  1. 1

    Words my hubby never thought he’d hear:
    ” Honey, let’s measure our thumbs so I can comment on my friend Donna’s blog post”! 🙂
    Our measurements? Roughly an inch! Who knew?
    Thanks for the illuminating posts. I bet you are good at logic and trivia games!
    Linda Kinsman recently posted..Wordless WednesdayMy Profile

  2. 2
    Angel Collins says:

    I never thought of measuring my thumb. Maybe after submitting this comment, I’d go and take a measurement. Nice trivia! Thanks.

  3. 3

    I do that!!! I use my thumb for roughly measuring an inch. 🙂 I find it comes in handy. 🙂 But I believe my thumb joint to tip is longer than an actual inch, though. 🙂
    Brook (Matt5vse6) recently posted..Faith. Hope. Love: Chapter SixMy Profile

  4. 4
    jessietaylor92 says:

    It never came to my mind t ask myself where it really started? And I didn’t bother at all to ask. It’s already understandable that when you see a person doing the thumb up, that means “are you okay?” or “it’s okay!”.
    Thanks to you, at least now I’m now I learned another trivia.

  5. 5
    LisaAnn says:

    Oh my gosh, I’ve always been told that the “rule of thumb” was some antiquated rule from Britain or somewhere that you were allowed to beat your wife with a stick as long as the width of that stick didn’t exceed the width of your thumb. I really like your explanation better, so I think I will officially switch over my thinking! 🙂

  6. 6
    Armand says:

    So what’s really the rule of thumb all about? It’s a mind boggling for me. If LisaAnn’s comment is true, my wife would rather left me for that. But she’s luck enough, I don’t beat my wife and it will never happen.

Leave a Reply

CommentLuv badge