Fear not, modern inches are metric inches: since the adoption of the international yard during the 1950s and 1960s, it has been based on the metric system and

Fear not, modern inches are metric inches: since the adoption of the international yard during the 1950s and 1960s, it has been based on the metric system and defined as exactly 25.4 mm. https://en.wikipedia.org/wiki/Inch https://en.wikipedia.org/wiki/Inch