Pure Alcohol Calculator — grams per drink
Add up the grams of pure alcohol in your drinks and compare with health guidelines — computed locally. Never a tool for judging driving: the only safe amount before driving is zero.
🔒 Runs entirely in your browser. Your input and output are never sent to a server or stored — fully private.
Add your drinks to see how many grams of pure alcohol they contain, compared with public-health guidance.
Moderate ≈ 20 g/day (Japan MHLW)
Elevated risk: 40 g+ men / 20 g+ women (Kenkō Nippon 21)
Pure alcohol (g) = volume (ml) × ABV⁄100 × 0.8
⚠ This is general health information, NOT medical advice. Alcohol tolerance varies greatly between individuals.
🚫 NEVER use this tool to judge whether you can drive. The only safe amount of alcohol before driving is ZERO — if you drink, do not drive. This tool deliberately gives no "time until sober" estimate; none would be safe.
⚠ If you are pregnant, may be pregnant, or have a medical condition affected by alcohol: do not drink.
About this tool
How much alcohol is actually in that drink? This calculator answers in grams of pure alcohol — the unit health guidelines use — from volume and ABV: ml × ABV% × 0.8 (the density of ethanol). Enter a 500 ml beer at 5% and you get 20 g, which is exactly Japan's MHLW benchmark for moderate daily drinking; other countries define their own guideline units. Add several drinks to total an evening honestly. It is a health-awareness tool, not a verdict on fitness to drive. Everything is computed locally in your browser and never uploaded.
Frequently asked questions
Why grams of pure alcohol instead of counting drinks?
Because "a drink" is wildly inconsistent: a 350 ml can of 5% beer carries 14 g of alcohol, a 180 ml glass of 15% sake about 21.6 g, and a 500 ml can of 9% chu-hai a hefty 36 g — two and a half times the beer. Grams make these comparable, and guidelines are written in grams: Japan's MHLW puts moderate drinking around 20 g per day on average, with lower amounts advised for women and people who flush. Note that guideline values differ by country.
Can I use this to decide whether I am OK to drive?
No — never. This tool must not be used to judge fitness to drive. The only safe amount of alcohol before driving is zero: if you drink, do not drive, full stop. Blood alcohol depends on body weight, sex, food, medication, fatigue and individual metabolism, so no calculator can tell you when you are safe — and impairment begins below any legal limit. That is also why this tool deliberately shows no "time until sober" estimate: such numbers invite exactly the gamble that kills people.
Is this medical advice? And is my drinking data private?
No — the guideline figures shown here are public-health information, not medical advice, and "moderate" is not a recommendation to drink; recent research finds risk rising from low levels. If you take medication, are pregnant, have liver or dependence concerns, or simply want personal guidance, talk to a doctor. Privacy is by design: what and how much you drink is sensitive, so every calculation runs in your browser and nothing is uploaded, stored or tracked.