Estimate your BAC based on drinks, weight, and time elapsed. Uses the Widmark formula. For awareness only — never use to decide if you can drive.
📋 Source: Blood alcohol concentration formula based on Widmark equation. Australian standard drink = 10g ethanol. NHMRC Australian Guidelines to Reduce Health Risks from Drinking Alcohol (2020). This calculator is a guide only — individual BAC varies significantly. Never drive if you have consumed alcohol. Your doctor or healthcare provider knows your history and circumstances — always follow their personalised advice over general information.
Never drink and drive. This is an estimate only — actual BAC varies widely. Legal limit for fully licensed drivers: 0.05%. Learner and P-plate drivers: 0.00%.
Biological sex
What have you drunk? (Australian standard drinks)
Total standard drinks: 0
0.000%
Blood Alcohol Concentration (BAC)
Enter your details above
Estimate only. The Widmark formula does not account for food intake, medications, liver health, fatigue, individual variation in metabolism, or the type of alcoholic beverage. BAC can be 20–30% higher or lower than estimated. The only accurate measure of BAC is a breath analysis (breathalyser) or blood test. If you have been drinking, do not drive.
If you are concerned about your alcohol use, the AUDIT-C screen can help you start a conversation with your GP. Take the AUDIT-C screen.
Australian standard drink guide (10g alcohol each)
Drink
Volume
Strength
Std drinks
Full-strength beer
285 mL (pot/middy)
4.8%
1.1
Full-strength beer
375 mL (can)
4.8%
1.4
Mid-strength beer
375 mL (can)
3.5%
1.0
Low-strength beer
375 mL (can)
2.7%
0.8
Table wine
100 mL
13%
1.0
Table wine
150 mL (restaurant pour)
13%
1.5
Spirits / whisky / vodka
30 mL (nip)
40%
1.0
RTD / alcopop
275 mL
5%
1.1
Champagne / sparkling
100 mL
12%
0.9
Sources
Widmark EMP. Principles and applications of medicolegal alcohol determination. 1932. (Widmark formula — basis of all BAC estimators)
Australian Government Department of Health. Standard drinks guide. health.gov.au
National Health and Medical Research Council (NHMRC). Australian Guidelines to Reduce Health Risks from Drinking Alcohol. 2020. nhmrc.gov.au
Transport for NSW / VicRoads. Drink driving facts. Elimination rate 0.015% BAC/hour.
DirectLine: 1800 888 236 (24/7 drug & alcohol counselling) · Counselling Online: counsellingonline.org.au For a full directory of support services, visit AskMyGP helplines directory.