A unit is not a glass
One UK unit is 10 ml of pure alcohol, approximately 8 g. It gives beer, wine and spirits a common measure. The size of the glass still matters.
UK units = volume in ml × strength as a percentage × quantity ÷ 1000. MeSober uses this calculation. A 500 ml beer at 5% contains 2.5 units.
Why does Spain show another number?
A Spanish unidad de bebida estándar, or UBE, contains 10 g of alcohol. The same 500 ml beer at 5% has about 20 g, or around 2 UBE. The alcohol has not changed; the measuring unit has.
The US has another measure
A US standard drink contains 14 g of pure alcohol. Our 20 g example works out to about 1.43 standard drinks. Comparing two numbers from different apps without checking the system is poor maths.
Make the numbers useful
Check the volume and ABV on the label, put them into the calculator and keep one system for your diary. The calculator’s gram figure is approximate, derived from UK units at 8 g per unit.
This measures alcohol content. It does not calculate blood alcohol concentration, determine when you can drive or give you a personal safe drinking allowance.
