The saying "rule
of thumb" refers to a general guideline, rather than a strict rule.
Thus “rule of thumb” is a common understanding which is based on experience or
general knowledge.
For Example:
“The usual rule of thumb says that to calculate when an
investment will double, divide 70 by the interest rate.”
This is the Idiom #85 in the List of 100 commonly used Idioms in everyday English (Top 100 famous Idioms). By introducing this list of notable idioms to English learners and ESL students as you, we believe that your English will sound more like a native and you can easily understand what native speakers are saying. Please like and share this list with your friends if you think it is helpful - the full list is here.
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