An events manager is planning a 3-hour dinner function for 60 guests. Before placing the drinks order with the wholesaler, they need the total beer, wine and spirits quantities with an appropriate split, and a standard drinks check for responsible service compliance.
Alcohol & Beverage Calculator
Beverages
e.g. beer 4.5% · wine 13% · spirits 40%
Standard drinks = Volume (mL) × ABV% × 0.000789
1 Australian standard drink = 10g of pure alcoholExamples: 375 mL beer 4.5% = 1.3 std · 150 mL wine 13% = 1.5 std · 30 mL spirits 40% = 1.0 std
Low-risk guidelines (NHMRC 2020): No more than 4 standard drinks on any single occasion · No more than 10 per week.
Results are estimates for planning purposes. Verify with current standards and a qualified professional.
1 What this calculator does
Runs in two modes. Standard drinks mode: calculates the number of standard drinks in a container from volume (mL) and ABV%. Event drinks mode: estimates total beer, wine and spirit quantities for an event from guest count, duration and preferred drink split. Flags Australian RSA guidelines.
2 Formula & professional reasoning
Standard drinks = Volume (mL) x ABV% / 100 x 0.789 / 10
(0.789 = density of alcohol in g/mL | 10 = grams per AU standard drink)
Event mode:
Drinks per person = Hours (if <=2: 1 per hour | >2: 2 + (hours-2) x 0.5 per hour)
Total drinks = Guests x Drinks per person x 1.10 (10% buffer)
Beer bottles = Total x Beer% | Wine bottles = (Total x Wine%) / 5 | Spirits = Total x Spirit%
An Australian standard drink contains exactly 10g of pure alcohol. The formula converts volume and ABV to grams of alcohol: mL x (ABV/100) gives pure alcohol mL, multiplied by 0.789 g/mL gives grams of alcohol. Dividing by 10 gives standard drinks. For events, consumption tapers after the first 2 hours -- guests drink approximately 1 drink per hour for the first 2 hours, then 0.5 per hour thereafter as they are socialising rather than drinking continuously. Responsible service of alcohol (RSA) requires knowing the standard drink count of every service.
3 Worked examples
⚠️ Illustrative example only — not clinical or professional instruction.
Basic
Standard drinks in a 750mL bottle of wine (13.5% ABV)
Given: Mode: standard drinks | Volume: 750mL | ABV: 13.5%
Working:
Standard drinks: 750 x 0.135 x 0.789 / 10 = 750 x 0.10652 / 10 = 79.89 / 10 = 7.99Answer: 7.99 standard drinks per bottle (approx 8) | Per 150mL glass: 1.6 standard drinks
💡 A standard wine glass pour (150mL at 13.5% ABV) is 1.6 standard drinks -- not 1.0. Many diners exceed the recommended 2 standard drinks per session with just 2 glasses of wine.
Standard
Event planning -- 60 guests, 3-hour dinner, 40/50/10 split
Given: Mode: event | Guests: 60 | Hours: 3 | Beer: 40% | Wine: 50% | Spirits: 10%
Working:
Drinks per person: 2 + (3-2) x 0.5 = 2.5 drinks | Total drinks: 60 x 2.5 x 1.10 = 165 | Beer: 165 x 0.40 = 66 bottles | Wine: ceil((165 x 0.50) / 5) = ceil(16.5) = 17 bottles | Spirits: 165 x 0.10 = 16-17 servesAnswer: Beer: 66 bottles/cans | Wine: 17 bottles (750mL) | Spirits: 16-17 standard serves | Total: 165 drinks
💡 This is the minimum order. For RSA compliance, also calculate: total standard drinks served per guest = 2.5 drinks per person. Ensure responsible service and food is provided throughout the event.
Advanced
Blood alcohol estimate for RSA compliance context
Given: Standard drinks consumed: 4 over 3 hours | Body weight: 70kg | Gender: male
Working:
BAC estimate (Widmark formula): (4 x 10 / (70 x 0.68 x 10)) - (0.015 x 3) = (40/476) - 0.045 = 0.084 - 0.045 = 0.039% | Legal limit: 0.05%Answer: Estimated BAC: 0.039% -- below 0.05% legal limit for this scenario
💡 BAC estimation is for educational reference only. Actual BAC depends on many individual factors. RSA staff should rely on observable behaviour indicators (slurred speech, unsteady gait, bloodshot eyes) rather than drink counting. The Widmark formula provides an approximation only.
4 Sanity check
Australian standard drink = 10g of pure alcohol
Full-strength beer 375mL 4.8%: 1.4 standard drinks | Wine 150mL glass 13%: 1.5 standard drinks | Spirit nip 30mL 40%: 0.95 standard drinks
AU RSA guidelines (NHMRC 2020)
Low-risk: no more than 4 standard drinks on any day | No more than 10 per week | Pregnant women and under 18: no safe level
Always provide non-alcoholic options and food
Eating slows alcohol absorption -- always serve food at events | Non-alcoholic alternatives are legally required at licensed premises in most states
Responsible Service of Alcohol (RSA)
All venue staff serving alcohol must hold an RSA certificate in most Australian states | RSA laws differ by state -- check your state's Office of Liquor and Gaming
5 Common errors
| Error | Cause | Consequence | Fix |
|---|---|---|---|
| Equating one glass of wine or one beer to one standard drink | Not checking the actual volume and ABV against the standard drink definition | Underestimating how many standard drinks guests have consumed -- RSA liability | A standard 150mL pour of 13% wine is 1.5 standard drinks, not 1.0. A 375mL full-strength beer at 4.8% ABV is 1.4 standard drinks. Always calculate actual standard drinks from volume and ABV, not the number of drinks served. |
| Not accounting for the tapering of consumption after the first 2 hours | Calculating 1 drink per person per hour for the full event duration | Significantly over-ordering for long events | Industry practice and research shows consumption tapers after the initial 2 hours. Use the event formula: 1 drink/hour for hours 1-2, then 0.5 drinks/hour for additional hours. A 5-hour event is not 5 drinks per person -- it is approximately 3.5 drinks per person. |
| Not providing adequate non-alcoholic alternatives at a licensed event | Focusing only on alcohol ordering | Non-drinkers, pregnant guests and guests who have reached their limit have nothing to drink -- hospitality failure and possible licence breach | Order a minimum of 1 non-alcoholic drink equivalent per guest for any event (sparkling water, juice, mocktails). RSA requires that non-alcoholic beverages be available at licensed premises in all states. |
| Serving alcohol to visibly intoxicated guests | Pressure from guests or event clients to continue serving | RSA liability, potential harm to the guest and third parties, licence breach and personal liability for the server | RSA trained staff must refuse service to visibly intoxicated guests regardless of who is paying for the event. Document refusals. The event organiser and licence holder bear responsibility for responsible service -- train all staff before each event. |
6 Reference & regulatory links
🇦🇺 Australia
7 Professional workflow
Common tools used alongside this one:
Food Cost Calculator
Food Cost Calculator -- beverage costs should be calculated alongside food costs for full event profitability analysis
→
Catering Quantity Calculator
Catering Quantity Calculator estimates food quantities for the same event -- plan food and drinks together
→
Tip & Bill Split
Tip and Bill Split Calculator handles the final bill split if guests are splitting beverage costs at the end of the event
→