A "standard drink" in Australia contains exactly 10 grams of pure alcohol — but almost no one can estimate how many standard drinks are in what they're actually drinking. The glass of wine poured at dinner, the schooner at the pub, the full-strength can from the fridge: each one contains more alcohol than most people assume. Here's how to understand and calculate it accurately.
Try it yourself: Use our free Alcohol Unit Calculator to calculate standard drinks for any beverage, and see how long alcohol takes to clear your system.
What Is a Standard Drink?
In Australia, one standard drink is defined as any drink containing 10 grams of pure alcohol. This is the national measurement used on all alcohol labels (required by law since 1995), in health guidelines, and in alcohol-related research.
Standard drinks = Volume (mL) × ABV% × 0.789 ÷ 10
0.789 is the density of ethanol in g/mL
Glass of wine: 150mL at 13.5% ABV
= 150 × 0.135 × 0.789 ÷ 10 = 1.6 standard drinks
Schooner of full-strength beer: 425mL at 4.9% ABV
= 425 × 0.049 × 0.789 ÷ 10 = 1.6 standard drinks
375mL can of full-strength beer at 4.9%
= 375 × 0.049 × 0.789 ÷ 10 = 1.45 standard drinks
Standard Drinks by Common Beverage
| Drink | Serving Size | Typical ABV | Std Drinks |
|---|---|---|---|
| Midstrength beer | 375mL can | 3.5% | 1.0 |
| Full-strength beer | 375mL can | 4.9% | 1.4 |
| Craft IPA | 375mL can | 6.5% | 1.9 |
| Schooner (beer) | 425mL | 4.9% | 1.6 |
| Pint (beer) | 570mL | 4.9% | 2.2 |
| Wine (restaurant pour) | 150mL | 13.5% | 1.6 |
| Wine (large restaurant) | 250mL | 13.5% | 2.7 |
| Wine (bottle) | 750mL | 13.5% | 8.0 |
| Champagne / Prosecco | 150mL flute | 12% | 1.4 |
| Spirits (single nip) | 30mL | 40% | 0.95 |
| Spirits (double nip) | 60mL | 40% | 1.9 |
| RTD / premix (can) | 375mL | 5% | 1.5 |
| RTD / premix (can) | 375mL | 7% | 2.1 |
Australian Low-Risk Drinking Guidelines
The Australian guidelines on alcohol use (updated 2020 by the NHMRC) provide the most current evidence-based recommendations:
- Guideline 1: To reduce health risks from alcohol, healthy men and women should drink no more than 10 standard drinks per week and no more than 4 standard drinks on any single day.
- Guideline 2: To reduce the risk of injury on a single occasion of drinking, drink no more than 4 standard drinks on a single occasion.
- Guideline 3: For people under 18, no alcohol is the safest option. For people 18–25, drinking less is safer.
- Guideline 4: For women who are pregnant, planning a pregnancy, or breastfeeding, not drinking alcohol is the safest option.
The 2020 guidelines halved the previous weekly limit (from 14 to 10 standard drinks) based on updated cancer research showing that alcohol is a Group 1 carcinogen with no safe threshold for certain cancers, particularly breast cancer and bowel cancer.
How Your Body Processes Alcohol
The liver metabolises alcohol at approximately one standard drink per hour for the average person. This rate is largely fixed — it does not speed up with coffee, food, or exercise. You cannot meaningfully speed up alcohol clearance.
Factors that affect your blood alcohol concentration (BAC) include:
- Body weight: Heavier people have more blood volume and body water to dilute alcohol.
- Sex: Women typically have less alcohol dehydrogenase (the enzyme that metabolises alcohol) and proportionally less body water, resulting in higher BAC for the same intake.
- Food: Eating slows alcohol absorption significantly — it doesn't reduce total alcohol absorbed, but blunts the peak BAC.
- Medications: Many medications interact with alcohol or affect metabolism.
- Genetic variation: Significant variation in alcohol metabolism exists between individuals and ethnic groups.
BAC and the Legal Driving Limit
In Australia, the legal BAC limit for fully licensed drivers is 0.05%. Learner and P-plate drivers must be at 0.00%. Professional drivers (trucks, buses) must also be at 0.00%.
There is no reliable rule of thumb for how many drinks keeps you under 0.05% — it depends too heavily on individual factors. The only safe approach if you intend to drive is not to drink, or to use a personal breathalyser and allow sufficient time to clear.
Rough estimate only (not for driving decisions):
A 70kg man who has consumed 3 standard drinks over 2 hours has a BAC of approximately 0.04–0.06%. A 60kg woman with the same intake may be at 0.06–0.08%. Individual variation is substantial.
Frequently Asked Questions
How many standard drinks are in a bottle of wine?
A 750mL bottle of wine at 13.5% ABV contains approximately 8 standard drinks. At 14.5% ABV (increasingly common for Australian reds), it's closer to 8.6 standard drinks. Most people underestimate this significantly.
Is low-alcohol beer much better?
Yes, proportionally. A mid-strength beer at 3.5% ABV contains about 1.0 standard drink per 375mL can versus 1.4–1.5 for full-strength. Zero-alcohol beers (<0.5% ABV) contain negligible alcohol. Switching to low-alcohol options is one of the most effective ways to stay under the guidelines.
Does eating while drinking really help?
It reduces peak BAC significantly by slowing gastric emptying and alcohol absorption. But it doesn't change how much total alcohol you absorb — it just spreads the absorption over a longer time. You'll still have the same total alcohol to metabolise.
How long until I'm sober after drinking?
At roughly one standard drink per hour of metabolism, a person who's had 6 standard drinks would take approximately 6 hours to clear the alcohol from their system — longer if they were drinking quickly. If you drank until midnight, you may still be above 0.05% at 6 AM.
Calculate your standard drinks
Use our Alcohol Unit Calculator to calculate the standard drinks in any beverage, estimate BAC, and see how long until alcohol clears your system.
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