How Much Bar Do You Need? A Drink Calculator Guide for Singapore Events

How Much Bar Do You Need? A Drink Calculator Guide for Singapore Events

One of the hardest numbers to pin down when planning an event bar is exactly how much alcohol and mixers to bring. Buy too little and the bar runs dry mid-reception; buy too much and you've overspent on bottles that go home unopened. Here's a simple way to calculate it, plus a real look at what BYOB actually costs versus paying bar prices per drink.

The Basic Formula

For a standard wedding reception with a general guest crowd, a good planning number is 2 cocktails per guest — one from each menu offered. For a 100-guest wedding, that works out to 200 cocktail portions across the two selections, or roughly 100 servings of each cocktail.

From there:

• Add a 20% buffer if there's an extended cocktail hour or open bar
• Reduce alcohol volume by 25–30% if a dedicated mocktail menu is also offered, since it pulls some guests toward non-alcoholic options

The Bottle Math

A standard 700ml bottle of spirit yields roughly 15 servings at a standard pour. That's the number to work backward from when figuring out how many bottles to bring for a BYOB bar.

Using the 100-guest example above: 100 servings of a single cocktail needs about 7 bottles of the base spirit (100 ÷ 15, rounded up).

What BYOB Actually Costs: Two Real Examples

With a BYOB mobile bar, the host supplies the base spirit and the bar service supplies the mixers, syrups, and garnishes at cocktail quality — priced per batch, not per portion. Here's what that looks like for two menu staples.

Whiskey Sour

• Client supplies: the whisky
• Bar service supplies: cocktail-quality lemon juice ($10, yields about 50 servings) and sugar syrup (yields a similar batch size)

Since the mixers are bought in bulk rather than per drink, the cost per serving stays low even at higher guest counts — the lemon juice and syrup for 50 Whiskey Sours costs a fraction of what a single bar-bought cocktail would cost on its own.

Margarita

• Client supplies: the tequila and triple sec
• Bar service supplies:
• Lime juice — $10, yields about 23 servings (~$0.44/serving)
• Sugar syrup — $5, yields about 46 servings (~$0.11/serving)
• Lime wheels — $10 for 45 pieces (~$0.22/serving)

That's roughly $0.77 per Margarita in mixers and garnish alone.

Tequila pricing typically runs:

• Jose Cuervo — around $50 per 700ml bottle
• Don Julio — around $75 per 700ml bottle

For 100 Margaritas (about 7 bottles of tequila), that's roughly $350 in Jose Cuervo or $525 in Don Julio, plus about $95 in mixers and garnish for the full batch (lime juice, sugar syrup, lime wheels at the yields above). All-in, that lands around $4.45 per Margarita with Jose Cuervo or $6.20 per Margarita with Don Julio — well under a bar or venue charging $20 per portion plus GST and service charge, which pushes a single bar-bought Margarita close to $24.

Why the Math Favours BYOB

The gap isn't just about the alcohol markup — it's that bar and venue pricing charges per portion, while a BYOB mobile bar service prices spirits and mixers per bottle or per batch. Buying 7 bottles of tequila and a few batches of mixers scales far better across a 100–200 guest event than paying a flat per-drink rate for every single pour.

This is also why fixed-price packages make budgeting easier for planners: once guest count and cocktail selection are set, the total cost is predictable rather than climbing with every extra round ordered.

Quick Reference: Servings Per Bottle/Batch

| Item | Yield | Approx. Cost |

|---|---|---|

| 700ml spirit bottle | ~15 servings | Client-supplied |

| Jose Cuervo tequila (700ml) | ~15 servings | ~$50/bottle |

| Don Julio tequila (700ml) | ~15 servings | ~$75/bottle |

| Lemon juice (cocktail quality) | ~50 servings | $10 |

| Lime juice (cocktail quality) | ~23 servings | $10 |

| Sugar syrup | ~46 servings | $5 |

| Lime wheels | 45 pieces | $10 |

Putting It Together for Your Guest Count

• Intimate events (around 30 guests): roughly 2–3 bottles of spirit per cocktail type, plus one batch of mixers per drink is usually enough.
• Mid-size to large events (up to 200 guests): scale bottle count using the 15-servings-per-bottle rule, and order mixers in the batch sizes above rather than estimating per portion. For a 100-guest wedding running two cocktails per guest, budget around 7 bottles of spirit per cocktail selection.

Getting these numbers right ahead of time is exactly what a fixed-price BYOB package is designed to simplify — the bar team can confirm exact quantities based on your final guest list and cocktail menu, so nothing runs short and nothing goes to waste.

Not sure how many bottles to bring for your guest count? Get a custom quote and the bar team will work out the exact quantities for your event.