Wine Serving Calculator
Calculating how much wine to buy for a party involves four variables: the number of guests, how many hours the event lasts, what percentage of guests will drink wine, and how many glasses per hour each wine drinker will have. A standard US wine glass pour is 5 fluid ounces (approximately 148 ml), giving exactly 5 glasses per 750 ml bottle. A reasonable starting assumption for a dinner party is that about 75% of guests drink wine at roughly 1 glass per hour. For a cocktail party or reception where wine is the primary drink, guests may have 1.5 to 2 glasses per hour. This calculator multiplies guests by the drinkers percentage by event hours by glasses per hour, then divides by 5 (glasses per bottle) to get the total bottles needed. It also shows how many cases (12 bottles each) to order and breaks the total into a red/white split that you can adjust. Always purchase a 10% to 15% buffer to avoid running short.
Consider purchasing 10% to 15% more than the calculated amount as a buffer.
Wine quantity quick reference
| Guests | 2-hour dinner | 3-hour dinner | 4-hour party |
|---|---|---|---|
| 10 guests | 3 bottles | 5 bottles | 6 bottles |
| 20 guests | 6 bottles | 9 bottles | 12 bottles |
| 30 guests | 9 bottles | 14 bottles | 18 bottles |
| 50 guests | 15 bottles | 23 bottles | 30 bottles |
Assumes 75% wine drinkers, 1 glass per hour, 5 oz pours, rounded up.
Wine serving: frequently asked questions
How many glasses are in a bottle of wine?
A standard 750 ml bottle of wine contains approximately 5 glasses, using a standard US pour of 5 fluid ounces (148 ml) per glass. At this pour size, five glasses exactly fill one bottle. Some restaurants pour 6-ounce pours, which yield approximately 4 glasses per bottle. This calculator uses the 5-ounce standard pour.
How many bottles do I need for 20 guests?
For 20 guests at a 2-hour dinner party where approximately 75% are wine drinkers consuming 1 glass per hour: 20 * 0.75 * 2 * 1 = 30 glasses. At 5 glasses per bottle, that is 6 bottles. It is wise to purchase 10% to 20% extra as a buffer. For a 20-person dinner, purchasing 7 to 8 bottles is prudent.
How many bottles are in a case of wine?
A standard case of wine contains 12 bottles (750 ml each). Cases are usually the most economical way to purchase wine, often with a discount of 10% to 20% versus single-bottle price. For large events, purchasing by the case simplifies ordering. This calculator shows total bottles and the equivalent in cases.
Should I serve equal amounts of red and white wine?
A 50/50 split of red and white is a safe default for mixed gatherings. Some events skew toward red (winter dinners, red meat menus) or white (summer parties, seafood). This calculator defaults to a 50/50 split but lets you adjust. Having a slightly higher proportion of white in summer and red in winter is a common practice.
How should I account for non-drinkers and beer or spirit drinkers?
The drinkers percentage input lets you estimate what proportion of guests will drink wine. If some guests prefer beer, spirits, or non-alcoholic beverages, reduce the wine drinkers percentage accordingly. For a mixed party with good beer and spirit options, 50% to 65% wine drinkers is often more realistic than 75%.
References
- Dietary Guidelines for Americans 2020-2025: dietaryguidelines.gov.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.