What this calculator does
Blood alcohol content (Widmark formula) works out rough estimate of blood alcohol content from drinks consumed, body weight and time elapsed. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
The inputs explained
| Field | What to enter |
|---|---|
| Drink volume (ml) | A number, measured in ml. Starts at 350. |
| Alcohol by volume (%) | A number, measured in %. Starts at 5. |
| Body weight (kg) | A number, measured in kg. Starts at 75. |
| Sex | Choose from Male, Female. |
| Time since drinking started (hours) | A number, measured in hours. Starts at 1. |
| Elimination rate (%/hour) | A number, measured in %/hour. Starts at 0.015. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with drink volume
Every other input is held at the calculator’s starting values while drink volume varies. Select any row to load that scenario into the calculator.