Can You Predict Tomorrow's Hangover?
How rough you feel the morning after drinking is closely tied to how much alcohol you consumed and the peak blood alcohol concentration (BAC) it produced. This calculator uses the widely-used Widmark formula, combining your weight, gender, drink volume, and ABV to estimate peak BAC and map it to a hangover severity range. It's a handy way to gauge your night out before you start drinking.
How the Calculation Works
Grams of pure alcohol are calculated from volume (ml) times ABV (%) times ethanol density (0.7936), then divided by your body weight and a water-distribution ratio (0.68 for men, 0.55 for women) to estimate BAC. Women generally have a lower body water ratio, so the same drinks produce a higher BAC compared to men of the same weight.
Remember: This Is an Estimate
Actual hangover severity depends heavily on food intake, sleep, hydration, and individual alcohol metabolism. Treat this result as a general reference only — never use it to judge whether you're safe to drive or perform other tasks requiring full sobriety.
Frequently Asked Questions
This tool uses the Widmark formula to estimate your peak blood alcohol concentration (BAC) from drink volume, ABV, weight and gender, then maps that BAC to a hangover severity range.
No. Actual hangover severity varies with individual tolerance, food intake, hydration, and sleep, so treat this as a rough estimate rather than an exact prediction.
Drinking water alongside alcohol, eating food while drinking, pacing yourself, and hydrating before bed can help. Reducing total intake is the most reliable way to avoid a severe hangover.