Wine for a Party Calculator

1. Enter the number of guests you expect.
2. Set the event length in hours.
3. Estimate the share who drink wine and pick a red and white split.
4. Read the bottles to buy, glasses, and cases.

Here is what each result means:

The standard planning rule is one glass of wine per drinker per hour. It keeps glasses topped up without overbuying, and it scales cleanly with the length of your event.

Only some guests drink wine, so the calculator applies your share first. A wine-focused dinner might be 100 percent, while a mixed party could be half.

A standard bottle of wine is 750 milliliters, which is 25 ounces. A restaurant pour is 5 ounces, so each bottle gives five glasses. That five-glasses-per-bottle figure is the key to turning glasses into bottles.

At home, pours are often larger, so five glasses per bottle is a safe planning number that leaves a little room.

The calculator finds how many guests drink wine, multiplies by glasses per person, then divides by five glasses per bottle and rounds up.

1. Multiply guests by the share who drink wine.
2. Multiply that by hours to get total glasses.
3. Divide glasses by five and round up to whole bottles.

The red and white split then divides those bottles by color for your shopping list.

Take 30 guests at a four hour party where 70 percent drink wine, split evenly by color.

Calculation: 70 percent of 30 is 21 wine drinkers. At one glass per hour for four hours, that is 84 glasses. Divided by five glasses per bottle and rounded up, you need 17 bottles, which is about a case and a half. An even split is roughly 9 red and 8 white.

Approximate bottles for a four hour event where about 70 percent drink wine.

Planning a Wedding

Turn a guest count into a bottle order, split by color, so the bar never runs dry.

Hosting a Dinner Party

Buy the right number of bottles for the table without a cupboard of leftovers.

Stocking a Bar

Estimate wine alongside other drinks so your budget and fridge space add up.

1. Counting Every Guest as a Drinker

Not everyone drinks wine. Set a realistic share so you do not overbuy for a mixed crowd.

2. Forgetting Larger Home Pours

Pours at home run bigger than a restaurant's five ounces. Buy a little extra if you pour generously.

3. Ignoring the Season and Menu

White and rose sell faster in summer, red in winter and with hearty food. Adjust the split to fit.

4. Cutting It Too Close

Wine keeps unopened, so rounding up is safe. Running short mid-event is the bigger risk.

The bottle math is exact once you set the inputs. The drinking rate is a planning average that varies with the crowd, the occasion, and the weather.

Plan about one glass per wine drinker per hour. Since a bottle holds five glasses, that is roughly one bottle for every five guest-hours of wine drinking.

A standard 750 milliliter bottle holds five 5 ounce glasses, the typical restaurant pour. Larger home pours give four glasses per bottle, so buy a little extra.

For a four hour event where about 70 percent drink wine, plan roughly 28 bottles for 50 guests. That is a little over two cases, split by color as you prefer.

For 100 guests over five hours with most drinking wine, plan around 60 to 75 bottles. Enter your exact numbers above for a precise count and a red and white split.

An even split works for most events. Lean white and rose for summer or lighter menus, and red for winter or hearty food, then adjust the split above.

A standard case holds 12 bottles. Buying by the case is often cheaper, and many stores discount a full case, so round your order up to the nearest case when you can.

Lower the share who drink wine to match. The rest of your bar can be planned separately, so you are not buying wine for guests who will not drink it.

No. The calculation runs in your browser and nothing you enter is stored or sent anywhere, unless you choose Save, which keeps the result only on this device.

• Standard drink (5 ounce wine serving).
• Wine bottle (750 ml bottle size).