When did it become common practice to list the metric measurement next to the imperial measurement on products at the supermarket? For example, something that is 1 pound had (454g) next to it, or one gallon (3.8L).
What was the first products that had this? When did it become common?
It started to show up in the early late 70’s. The first food I remember with both systems are the plastic bottles of pop that came out in 2 liter bottles.
In the mid 70s in middle school there was a big push to learn metrics. I recall the 2 liter cokes came out around then. They had 3 liter bottles for a short time as well. Congress passed some laws to help the move to the metric system but it never really caught on in most industries.
Much of it started with the Metric Conversion Act of 1975, which was voluntary. Since 1992, the federal Fair Packaging and Labeling Act (FPLA) has required consumer goods to be labeled in both customary and metric units.