Alcohol Per Guest Calculator
Planning a party and wondering how much alcohol to buy? This calculator uses the standard catering rule: 1 drink per guest per hour for the first 2 hours, then 0.5 drinks per hour after that. It splits the total across 50% wine, 30% beer, and 20% spirits, then converts everything into bottles, cans, and liters so you know exactly what to buy.
When to use this calculator
- Estimating alcohol quantities for a wedding reception
- Planning a cocktail party without over- or under-buying
- Budgeting alcohol costs for a corporate event
- Calculating bar supplies for a birthday or anniversary party
- Comparing drink needs for different event durations
- Adjusting quantities for light vs. heavy drinking crowds
How it works
2 min readWhat is the standard alcohol consumption rate per guest?
The standard catering rule estimates 1 drink per guest per hour for the first 2 hours, then 0.5 drinks per hour thereafter. For a 4-hour event with 100 guests, this typically totals 300 drinks, split into 50% wine, 30% beer, and 20% spirits, requiring approximately 42 wine bottles and 126 beers.
How It Works
This calculator applies the standard bar catering formula used by professional event planners and caterers across the US.
Formula
// Step 1: Total drinks
First 2 hours: guests × 1 drink/hr × min(hours, 2)
Remaining hrs: guests × 0.5 drink/hr × max(hours - 2, 0)
Total drinks = first_block + second_block
// Event-type multipliers (consumption tendency)
Wedding: ×1.0 (standard)
Cocktail: ×1.15 (higher — drinks-focused format)
Casual: ×0.85 (lower — food competes, mixed audiences)
// Step 2: Split by drink type
Wine drinks = total_drinks × 0.50
Beer drinks = total_drinks × 0.30
Spirit drinks = total_drinks × 0.20
// Step 3: Convert to purchasable units
Wine bottles = ceil(wine_drinks / 5) // 750 mL bottle ≈ 5 x 5 oz pours
Beers = ceil(beer_drinks / 1) // 1 drink = 1 can/bottle (12 oz)
Spirits (L) = spirit_drinks × 0.044 // 1 spirit drink ≈ 1.5 oz = 0.044 L
Spirit bottles= ceil(spirits_L / 0.75) // 750 mL per bottleWorked Example
Input: 80 guests, 5-hour wedding
| Step | Calculation | Result |
|---|---|---|
| Drinks (first 2 hrs) | 80 × 1 × 2 | 160 |
| Drinks (next 3 hrs) | 80 × 0.5 × 3 | 120 |
| Total (×1.0 wedding) | 160 + 120 | 280 drinks |
| Wine (50%) | 280 × 0.50 / 5 | 28 bottles |
| Beer (30%) | 280 × 0.30 | 84 cans |
| Spirits (20%) | 280 × 0.20 × 0.044 L | 2.46 L → 4 bottles |
Cost estimate at $15/wine, $10/6-pack, $25/spirit bottle:
The calculator also adds a 10% buffer for the high-end estimate to account for spillage, unexpected guests, or heavier drinkers.
Assumptions & Limitations
Frequently asked questions
What is the standard drink rule for events?
The industry standard used by US caterers is 1 drink per guest per hour for the first 2 hours, then 0.5 drinks per hour for each additional hour. This accounts for the fact that consumption tapers off as the event progresses and guests shift to food, dancing, or conversation.
How many glasses of wine are in a 750 mL bottle?
A standard 750 mL bottle yields approximately 5 glasses at a 5 oz pour, which is the US standard serving size for wine. Some venues pour 6 oz, which gives roughly 4 glasses per bottle. This calculator uses 5 glasses per bottle.
Why does a cocktail party need more alcohol than a wedding?
Cocktail parties are drink-centric by design — guests arrive expecting to hold a glass the whole time, and there is typically less food to slow consumption. This calculator applies a 1.15× multiplier for cocktail events compared to the baseline wedding format.
Should I buy extra as a buffer?
Yes. Professional planners recommend buying 10–15% more than the calculated amount. Running out of alcohol mid-event is far worse than having leftovers. Many retailers also allow unopened returns, so over-buying carries low risk. The 'high' cost estimate in this calculator already includes a 10% buffer.
How much alcohol does a 100-guest, 4-hour wedding need?
Using this calculator's formula: 100 guests × (2 hrs × 1 + 2 hrs × 0.5) = 300 drinks. Split: 150 wine drinks (30 bottles), 90 beers, 60 spirit drinks (≈2.6 L / 4 bottles of 750 mL). At average US prices (~$15 wine, ~$10 six-pack, ~$25 spirits), expect $700–$800.
What if many guests don't drink alcohol?
Subtract non-drinkers from the guest count before entering it. For example, if 100 guests are attending but 20 don't drink, enter 80 in the guest field. The formula does not automatically account for abstainers, designated drivers, or underage guests.
Does this include beer kegs?
This calculator outputs individual 12 oz cans/bottles for simplicity. If you prefer kegs: a standard half-barrel (15.5 gal) yields about 165 twelve-oz servings; a quarter-barrel (7.75 gal) yields about 82 servings. Divide the beer count accordingly.
Are mixers and non-alcoholic drinks included?
No. This calculator covers only beer, wine, and spirits. For mixers, a common rule is 1 liter of mixer (soda, juice, tonic) per 2 spirit drinks. For non-alcoholic options, plan at least 1–2 non-alcoholic drinks per guest across the full event duration.
How accurate are the cost estimates?
The estimates use the prices you enter for wine bottles, beer six-packs, and spirit bottles. Default prices ($15 wine, $10 six-pack, $25 spirits) reflect mid-range US retail in 2026. Costs vary by state, store, and brand — these figures are planning baselines, not quotes.