One interesting fact about US food labeling requirements is that manufacturers are legally required to use incorrect conversion ratios. Per the law 21 CFR 101.

One interesting fact about US food labeling requirements is that manufacturers are legally required to use incorrect conversion ratios. Per the law 21 CFR 101.9(b)(5)(viii) [0]: > (viii) For nutrition labeling purposes, a teaspoon means 5 milliliters (mL), a tablespoon means 15 mL, a cup means 240 mL, 1 fl oz means 30 mL, and 1 oz in weight means 28 g. In reality: * 1 fl. oz. ≈ 29.57 mL [1] (the volume measurements all build off of one another so I won't bother converting more than one) * 1 oz. ≈ 28.35 g In other words, volume and mass measurements are legally required to be off by ~1.4% and ~1.3% respectively. [0]: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm?fr=101.9 https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfr... [1]: https://en.wikipedia.org/wiki/Fluid_ounce https://en.wikipedia.org/wiki/Fluid_ounce