Presidential candidate and former Rhode Island Governor Lincoln Chafee has promised he will switch the United States to the metric system in the exceedingly unlikely event he ends up in the White House. While the idea may help him among the Europhile segments of the Democratic base, it’s a truly terrible one. Indeed, the forced metrication Chafee seems to want would intrusive, expensive, and counterproductive.

To start with, Americans already do use the metric system – formally, the International System of Units, or SI – where it has obvious benefits. The metric system is nearly universal in the laboratory sciences, nutrition, pharmaceuticals, and many areas of engineering (although measurements of torque and ballistics still commonly make use of the foot-pound of force, rather than the joule.) The law, through government departments of weights and measures, defines customary units like the foot, the pound and the gallon in terms of meters, kilograms and liters. Americans regularly buy two-liter bottles of soda and take part in 5K races.