back-of-the-envelope

EnglishEdit

EtymologyEdit

From the idea that the calculation or reasoning would be jotted down on any available scrap of paper such as the actual back of an envelope.

AdjectiveEdit

back-of-the-envelope

  1. (idiomatic) Approximate, rough, simplified, especially of a calculation, estimation or other reasoning.
    Do some back-of-the-envelope calculations before all the facts come in.