Calculation methodology and assumptions

This page documents the assumptions used in the current implementation. The calculation has not been clinically validated and is not guaranteed to match a measurement.

Ethanol and distribution

Ethanol (g) = ml × ABV / 100 × 0.789. Modelled dose = grams / (kg × r). Ethanol density is about 0.789 g/ml; r is 0.68 or 0.55, depending on the selected model.

Multiple drinks

The model divides each drink into 60 equal portions across the drinking period. A zero-length period is treated as one portion. Each portion is modelled as absorbing linearly over 45 minutes.

Elimination

The model orders absorption start and end events. Between events, the shared level changes by active absorption minus 0.15‰ per hour. It never falls below zero.

Time to zero and rounding

The chart, timeline and countdown use the same model. The estimated time to zero is rounded up to the next minute.

Input limits

The input limits are 20–300 kg for weight, up to 5,000 ml for volume and 0–100% ABV. These are technical limits; they do not mean the model is suitable for everyone within that range.

What the model cannot account for

The model does not measure individual metabolism or include clinical data. Drink strengths in the catalogue are approximate. Do not use it for medical or legal decisions or to assess whether someone can drive.