The same beverage produces different unit counts
A drink containing 28 grams of ethanol equals 2 U.S. standard drinks, 3.5 UK units, 2.8 Australian standard drinks, or about 2.1 Canadian standard drinks. The ethanol amount is unchanged; the national unit definition changes.
Country comparison
Why this matters for an EtG calculator
The main EtG calculator uses U.S. standard drinks because controlled research often reports exposure in grams or U.S.-style drink equivalents. A UK visitor entering “three units” as “three drinks” would overstate ethanol exposure. These localized calculators convert local quantities before the estimate.
What does not change by country?
Ethyl glucuronide is the same ethanol metabolite, and the uncertainty factors remain similar: total dose, time since drinking, repeated exposure, urine concentration, renal function, assay method, and laboratory cutoff. Country pages do not claim that biology changes at a border.
Scope: these pages explain official alcohol-unit definitions. They do not provide country-specific legal, employment, court, or supervision advice.