Figuring out how much alcohol to buy for a party is the one job every host either over-thinks or ignores until it's too late. Buy too little and you're the host doing a beer run at 10 PM. Buy too much and you've got nine bottles of warm white wine living in your basement until next summer. This is the calculator we walk Niagara and Hamilton hosts through every weekend — the rule, the bottle math, the ready-to-buy counts by party size, and the backup plan for when the count still comes up short.
The one rule that does 80% of the work
There's a single rule of thumb that gets you most of the way there: two drinks per guest in the first hour, then one drink per guest for every hour after.
People drink fastest at the start — the room is filling, everyone's got a glass, nobody's eaten yet. After the first hour it settles to a steadier pace. So the formula is:
Total drinks = guests × (1 + number of hours)
A four-hour party for 20 people works out to 20 × 5 = 100 drinks. A three-hour party for 10 works out to 10 × 4 = 40 drinks. That's your target number before you split it across beer, wine, and spirits.
Two adjustments to make it accurate for your crowd:
- Heavy-drinking crowd or a late-night party? Add 20%. Stags, post-shift industry nights, and "this is going till 3 AM" parties pour faster than a dinner gathering.
- Dinner party or a daytime BBQ with food out the whole time? Drop it 15–20%. Food slows everyone down, and daytime drinkers pace themselves.
The bottle math — how many drinks are actually in a bottle
The reason hosts miscount is they buy in bottles but plan in drinks. Here's the conversion, using standard Ontario pours (1.5 oz of spirits, 5 oz of wine, one beer):
- 750ml bottle of spirits (vodka, gin, tequila, rum, whiskey) → about 16 drinks
- 1.14L bottle of spirits (the big bottle) → about 25 drinks
- 750ml bottle of wine → about 5 glasses
- One beer (bottle or can) → 1 drink, so a 12-pack is 12 and a 24-case is 24
- 750ml bottle of sparkling → about 6 small toast pours, or 5 full glasses
So if your target is 100 drinks and you went all-spirits, that's roughly six 750ml bottles plus mixers. Nobody does all-spirits — but that's the unit you're working in. Keep this list handy; the rest of the calculator is just dividing your drink target across these three columns.
The calculator — ready-to-buy counts by party size
Most parties land on a mixed bar: some beer, some wine, some spirits or cocktails. A reliable split for a general crowd is roughly 40% beer, 30% wine, 30% spirits/cocktails. Adjust toward whatever your people actually drink — a backyard BBQ skews beer, a dinner party skews wine, a cocktail night skews spirits.
Here's what that looks like, fully worked out, for the four party sizes we get asked about most.
Small gathering — 8–10 guests, ~3–4 hours (≈40–50 drinks)
- Beer: one 12-pack (or a 24-case if it's a beer crowd) — browse beer
- Wine: 3–4 bottles, split red and white — a Gato Negro Cabernet and a Pinot Grigio cover both camps
- Spirits: one 750ml of a crowd-friendly mixer like Tito's or José Cuervo Silver, plus mixers
- One bottle of sparkling for a toast — Luc Belaire Rosé does the job and looks the part
Medium party — 15–20 guests, ~4 hours (≈80–100 drinks)
- Beer: two 24-cases (mix a Molson Canadian and a Corona so there's range)
- Wine: 6 bottles — 3 red, 3 white, chilled and ready
- Spirits: two 750ml bottles, or one 1.14L big bottle if you're doing a signature cocktail in batches
- Mixers: see the section below — this is the size where people start running out of tonic and ice first
Large party — 30–40 guests, ~5 hours (≈180–240 drinks)
- Beer: four to five 24-cases across two or three brands
- Wine: 12–15 bottles, weighted toward whatever the room drinks
- Spirits: four to six 750ml bottles, or two to three 1.14L big bottles — pick one or two signature cocktails instead of a full open bar so the count stays predictable
- Sparkling: 3–4 bottles if there's a toast
Big event — 40+ guests
Past 40 people, stop buying by the bottle and buy by the case and the cocktail. Pick one or two signature drinks (a batched margarita and a beer-and-wine table is the easiest open bar to run), calculate the spirits for the cocktail, and let beer and wine carry the rest. This is also the point where it pays to have a delivery line on standby rather than a second trip to the store.
Match the buy to the party — five common types
The 40/30/30 split is the default, but the kind of party shifts it:
The backyard BBQ / Canada Day cookout. Beer-forward — push to 55% beer, 25% wine (whites and rosé, served cold), 20% spirits. Corona and Coors Light outsell everything on a hot afternoon. Add a batched pitcher cocktail and extra ice.
The cocktail party. Spirits-forward — 50% spirits, 30% wine, 20% beer. Pick two signature cocktails so you're buying for two recipes, not ten. Our home bar guide covers the bottles and tools if you're hosting these regularly.
The dinner party. Wine-forward — plan one bottle of wine per two guests across the meal, plus an aperitif and a digestif. Less beer, more range in the wine.
The stag / stagette / late-night party. Add 20% to everything and weight toward spirits and beer. These run long and pour fast. If it's a Niagara Falls or Niagara-on-the-Lake weekend in a rental, plan for the night to outlast the LCBO by hours.
The wedding / big celebration. Beer and wine table plus one or two batched signature cocktails. Use the large-event approach above and over-buy sparkling — toasts always need more than you think.
The mixers, ice, and garnishes everyone under-buys
This is where good counts fall apart. The spirits are right, then the tonic runs out an hour in. Budget for:
- Mixers: about 1 litre of mixer for every 3 guests. Tonic, soda, cola, ginger ale, and at least one juice (cranberry or orange). Buy more than feels reasonable — flat warm pop is the one thing nobody will drink.
- Ice: 1 pound (about 0.5 kg) of ice per guest for a normal party — and double it for a hot day or an outdoor event. Ice for chilling bottles is separate from ice for glasses. This is the number-one thing hosts run out of.
- Garnishes: limes and lemons (one of each per 6–8 guests), plus whatever your signature cocktail needs.
- Non-alcoholic options: plan 2–3 non-alc drinks per guest. Sparkling water, a mocktail, and a soft drink. Designated drivers and non-drinkers go through more than you'd expect, and it keeps everyone pacing.
The Ontario specifics — bottle sizes, HST, and what's open late
A few things that change the math specifically for Ontario hosts:
- Bottle sizes are standardized. Spirits come in 750ml and the larger 1.14L; the big bottle is the better value for batching and groups.
- HST is on top. The shelf price isn't the final price — add 13% HST to your budget so the total doesn't surprise you at checkout.
- The LCBO closes early. Most locations shut at 9 PM, some at 11 PM, and Sundays close as early as 5 or 6 PM. The Beer Store closes earlier still. Plan your shop before the party, not during it.
- Statutory holidays close the LCBO entirely. This matters for the calendar this post lands on: the LCBO is closed on Canada Day (Wednesday, July 1, 2026). If you're hosting that day, buy by June 30 — or have an after-hours line ready.
The five mistakes that wreck the count
- Counting bottles instead of drinks. "Six bottles of wine sounds like plenty" — that's 30 glasses, gone in the first 90 minutes of a 20-person party.
- Forgetting the first-hour surge. People drink double at the start. Plan for two in hour one or you're short before dinner.
- Under-buying ice and mixers. The spirits are useless without them, and they're the first things to run out.
- Buying only what you like. Half your guests want red, the other half want white; some only drink beer. Cover the range, not your preference.
- Shopping during the party. The LCBO is already closed by the time you realize you're short. Buy ahead — and know your backup.
The backup plan — running short at 10 PM
Even a perfect count can come up short when the party runs long or twice as many people show up as RSVP'd. That used to mean the night was over. It doesn't anymore.
After Dark Quick delivers across the Niagara region and GTA West, 24/7 — under 60 minutes in our primary zone (Niagara Falls, St. Catharines, Welland, Thorold, Hamilton, Burlington, and more), 60–90 minutes to the extended edge. When the wine runs out at 10 PM, the full menu is still open: a case of beer, a few more bottles of wine, another vodka or tequila for the pitchers — quoted up front, ID checked at the door, no surprise fees. Call 416-627-7846 and the shelf reopens.
For the full picture of how after-hours delivery works in Ontario, see our guide on 24 hour alcohol delivery.
FAQ — how much alcohol to buy for a party
How much alcohol do I need for 20 people? For a four-hour party, plan about 100 drinks total — roughly two cases of beer, six bottles of wine, and two 750ml bottles of spirits with mixers, using a standard mixed-bar split. Adjust toward whatever your crowd actually drinks.
How many drinks are in a 750ml bottle? About 16 drinks of spirits (at a 1.5 oz pour), or about 5 glasses if it's wine. The larger 1.14L spirit bottle holds about 25 drinks.
How much wine for a dinner party? Plan one 750ml bottle for every two guests across the meal — each bottle is about 5 glasses. Add an extra bottle or two for the aperitif and the lingerers.
How much ice should I buy? One pound per guest for a normal party, doubled for a hot day or an outdoor event. Keep ice for chilling bottles separate from ice for glasses — they're two different piles.
What if I run out during the party? Call 416-627-7846. We deliver beer, wine, and spirits 24/7 across the Niagara region and Hamilton area — under an hour in the primary zone, price quoted up front.
Is the LCBO open on Canada Day? No — the LCBO is closed on Canada Day (July 1). Buy ahead by June 30, or use an after-hours delivery service for anything you run short on.
Buy once, host easy
The whole calculator comes down to three steps: get your drink target (guests × hours + 1), split it across beer, wine, and spirits for your crowd, and over-buy ice and mixers. Do that and you're covered for the night — without a basement full of leftovers.
And when the count still comes up short, you're not stuck. We deliver across all 14 service areas, 24 hours a day. Order direct at 416-627-7846, browse the full bottle menu, or check your service area for an ETA.
