What Is a Nomogram and Why Would It Interest Me?

A nomogram is a graphical diagram with numbered scales that allows users to calculate complex mathematical formulas by simply placing a straightedge across known values to find an unknown result. Invented in 1880 by Philbert Maurice d'Ocagne, nomograms were extensively used by engineers before electronic calculators became available, and they remain useful today for quick, practical calculations in fields such as medicine, ballistics, and construction. Though less common now, nomograms are inexpensive to produce, easy to use, and can solve equations with three or more variables that would be difficult to calculate by hand.