“I use the analogy of an iceberg,” she says. On the surface are U.S. imperial units, but many industries already use metric measurements, including food labels, car speedometers, and thermometers.

Metric units have conquered the globe, but in the US and the UK, their presence has become part of a culture war between “traditional” and “progressive” values. This is an extract from ...

Britain officially converted to the metric system in 1965, but just like the commonwealth countries of Canada and Australia, there’s still a mix of measurements—both metric and imperial—in ...