Your drinks
Drinks
Choose a drink to fill in its usual serving and strength, then change them to match your glass. A time after midnight counts as the same night.
Enter a valid weight, and an amount, strength and time for every drink, to see the estimate.
Your estimated blood alcohol peaks at 0.069% around 22:15 and is back to zero at about 02:50.
The purple line is your estimated blood alcohol. The ticks on the bottom axis are your drinks, and the green dot is the time it reaches zero.
Do not use this to decide whether to drive. The result is an estimate from population averages. Food, medicines, health and how fast you drink change your real blood alcohol, and alcohol slows your reactions well below any legal limit. If you drink, do not drive.
Track your blood alcohol on your phone
Log your drinks in WaterChamp and it estimates your blood alcohol with the same model as this calculator, and shows when it will be back to zero.
- Beer, wine, cocktails and spirits at their real strength
- Your estimate and the time it reaches zero
- Alcohol written to Apple Health on iPhone
Free on iPhone and Android. The forecast part of the chart is in WaterChamp Pro. It is an estimate: never use it to decide whether to drive.
How the estimate works
The pure alcohol in a drink is its volume times its strength times 0.789, the weight of one millilitre of alcohol in grams. A 500 ml beer at 5% holds 20 g. The Widmark formula turns grams into blood alcohol: the grams divided by your weight in kilograms times a body-water factor.1 The calculator uses Widmark's own factors, 0.68 for men and 0.55 for women, and their average, 0.615, when sex is not specified.
Each drink reaches the blood over about 45 minutes, so the calculator spreads it over that time. After that, your blood alcohol falls by 0.015% an hour, the average rate for moderate drinkers.2 Measured rates run from about 0.010% to 0.035% an hour, so two people with the same drinks can reach zero hours apart.
The formula gives grams of alcohol per kilogram of blood. The page divides that by 10 to show a percentage, the way BAC is written in the US: 0.8‰ is 0.08%. Laboratories measure per volume of blood, which reads a few percent higher.
BAC chart by body weight
Estimated peak blood alcohol after a number of US standard drinks, 14 g of alcohol each, finished within 45 minutes. Subtract about 0.015% for every hour since your first drink.
Men
| Drinks | 120 lb 54 kg | 140 lb 64 kg | 160 lb 73 kg | 180 lb 82 kg | 200 lb 91 kg | 220 lb 100 kg | 240 lb 109 kg |
|---|---|---|---|---|---|---|---|
| 1 | 0.038% | 0.032% | 0.028% | 0.025% | 0.023% | 0.021% | 0.019% |
| 2 | 0.076% | 0.065% | 0.057% | 0.050% | 0.045% | 0.041% | 0.038% |
| 3 | 0.113% | 0.097% | 0.085% | 0.076% | 0.068% | 0.062% | 0.057% |
| 4 | 0.151% | 0.130% | 0.113% | 0.101% | 0.091% | 0.083% | 0.076% |
| 5 | 0.189% | 0.162% | 0.142% | 0.126% | 0.113% | 0.103% | 0.095% |
| 6 | 0.227% | 0.195% | 0.170% | 0.151% | 0.136% | 0.124% | 0.113% |
Women
| Drinks | 120 lb 54 kg | 140 lb 64 kg | 160 lb 73 kg | 180 lb 82 kg | 200 lb 91 kg | 220 lb 100 kg | 240 lb 109 kg |
|---|---|---|---|---|---|---|---|
| 1 | 0.047% | 0.040% | 0.035% | 0.031% | 0.028% | 0.026% | 0.023% |
| 2 | 0.094% | 0.080% | 0.070% | 0.062% | 0.056% | 0.051% | 0.047% |
| 3 | 0.140% | 0.120% | 0.105% | 0.094% | 0.084% | 0.077% | 0.070% |
| 4 | 0.187% | 0.160% | 0.140% | 0.125% | 0.112% | 0.102% | 0.094% |
| 5 | 0.234% | 0.200% | 0.175% | 0.156% | 0.140% | 0.128% | 0.117% |
| 6 | 0.281% | 0.241% | 0.210% | 0.187% | 0.168% | 0.153% | 0.140% |
How long does it take to sober up?
At the average rate, blood alcohol falls by 0.015% an hour. From 0.08%, the driving limit in most US states, that is about 5 hours and 20 minutes to zero. For a 70 kg man the rate is about 7 g of alcohol an hour, half of a US standard drink. For a 70 kg woman it is about 6 g. Only time lowers it: coffee, water, food and a cold shower leave the rate the same.
| Blood alcohol | Time to zero at 0.015% an hour |
|---|---|
| 0.02% | 1 h 20 min |
| 0.05% | 3 h 20 min |
| 0.08% | 5 h 20 min |
| 0.10% | 6 h 40 min |
| 0.15% | 10 h |
| 0.20% | 13 h 20 min |
How much alcohol is in one drink
A US standard drink holds 14 g of pure alcohol: 12 fl oz of 5% beer, 5 fl oz of 12% wine, or 1.5 fl oz of 40% spirits.3 A UK unit is 8 g. Many real pours hold more. The table lists the servings that this calculator and the app start from.
| Drink | Serving | Strength | Alcohol | US standard drinks |
|---|---|---|---|---|
| Long Island Iced Tea | 300 ml (10.1 fl oz) | 16% | 38 g | 2.7 |
| Margarita | 240 ml (8.1 fl oz) | 13% | 25 g | 1.8 |
| Beer | 500 ml (16.9 fl oz) | 5% | 20 g | 1.4 |
| Cosmopolitan | 120 ml (4.1 fl oz) | 20% | 19 g | 1.4 |
| Espresso Martini | 120 ml (4.1 fl oz) | 20% | 19 g | 1.4 |
| Irish Coffee | 240 ml (8.1 fl oz) | 10% | 19 g | 1.4 |
| Mojito | 240 ml (8.1 fl oz) | 10% | 19 g | 1.4 |
| Cider | 500 ml (16.9 fl oz) | 4.5% | 18 g | 1.3 |
| Martini | 90 ml (3 fl oz) | 25% | 18 g | 1.3 |
| Gin & Tonic | 200 ml (6.8 fl oz) | 10% | 16 g | 1.1 |
| Mulled Wine | 200 ml (6.8 fl oz) | 10% | 16 g | 1.1 |
| Raki | 45 ml (1.5 fl oz) | 45% | 16 g | 1.1 |
| Red Wine | 150 ml (5.1 fl oz) | 13.5% | 16 g | 1.1 |
| Rum & Coke | 180 ml (6.1 fl oz) | 11% | 16 g | 1.1 |
| White Wine | 150 ml (5.1 fl oz) | 12.5% | 15 g | 1.1 |
| Bloody Mary | 150 ml (5.1 fl oz) | 12% | 14 g | 1.0 |
| Brandy | 45 ml (1.5 fl oz) | 40% | 14 g | 1.0 |
| Champagne | 150 ml (5.1 fl oz) | 12% | 14 g | 1.0 |
| Gin | 45 ml (1.5 fl oz) | 40% | 14 g | 1.0 |
| Hard Seltzer | 355 ml (12 fl oz) | 5% | 14 g | 1.0 |
| Hugo | 250 ml (8.5 fl oz) | 7% | 14 g | 1.0 |
| Rosé Wine | 150 ml (5.1 fl oz) | 12% | 14 g | 1.0 |
| Rum | 45 ml (1.5 fl oz) | 40% | 14 g | 1.0 |
| Sangria | 200 ml (6.8 fl oz) | 9% | 14 g | 1.0 |
| Spirit | 45 ml (1.5 fl oz) | 40% | 14 g | 1.0 |
| Vodka | 45 ml (1.5 fl oz) | 40% | 14 g | 1.0 |
| Whiskey | 45 ml (1.5 fl oz) | 40% | 14 g | 1.0 |
| Aperol Spritz | 200 ml (6.8 fl oz) | 8% | 13 g | 0.9 |
| Prosecco | 125 ml (4.2 fl oz) | 11% | 11 g | 0.8 |
| Radler | 500 ml (16.9 fl oz) | 2.5% | 10 g | 0.7 |
| Vermouth | 75 ml (2.5 fl oz) | 16% | 9 g | 0.6 |
| Mimosa | 150 ml (5.1 fl oz) | 6% | 7 g | 0.5 |
In the app
The WaterChamp app logs alcohol with your other drinks. It shows your current blood alcohol and the time it reaches zero, and Pro adds this curve for the hours ahead. It also counts days without alcohol for the Dry Week and Sober Month stickers. Alcohol lowers how much a drink counts toward your water goal; see beer and wine, or every drink in the drink guide.
1. Reiter GS, Boeckle M, Reiter C, Seltenhammer MH. "The impact of total body water on breath alcohol calculations." Wiener klinische Wochenschrift, 2020;132(17):535-541. pmc.ncbi.nlm.nih.gov/articles/PMC7518982
2. Jones AW. "Evidence-based survey of the elimination rates of ethanol from blood with applications in forensic casework." Forensic Science International, 2010;200(1-3):1-20. pubmed.ncbi.nlm.nih.gov/20304569
3. National Institute on Alcohol Abuse and Alcoholism. "What is a standard drink?" niaaa.nih.gov
