How many carbon has the simplest cycloalkane?

And thus the smallest cycloalkane is $\text{cyclopropane}$, ${C}_{3} {H}_{6}$. The ring junction introduces a so-called $\text{degree of unsaturation}$. $\text{Cyclopropane}$ has 2 hydrogens LESS than fully saturated $\text{propane}$, ${C}_{3} {H}_{8}$.