Working Out A Birthday Party Bill In Four Steps

Whoever organises the party usually has to answer one question before calling the venue: "Roughly what will this come to?" — and being able to answer it with your own figure makes the decision much easier.

The formula the venue uses is one line:

(discounted room rate + set menu + drinks) × 1.155

The 1.155 covers the 5% service charge and 10% VAT. The four steps below unpack that line.

Step 1: the room rate before any discount

Take the hourly room rate and multiply by the hours. The most common party booking is four hours.

The example used throughout: a group of 35 in room 555 Starship (80m², 750,000đ per hour), four hours.

750,000đ × 4 = 3,000,000đ

Step 2: take the discount off the room rate

Take one of the two offers, whichever is larger. At 50, the birthday discount gives 50%, more than the 30% of the time-slot offer.

3,000,000đ × 50% = 1,500,000đ off

Room rate remaining: 1,500,000đ

Step 3: add the set menu and drinks, both at full price

The discount does not touch either. The set menu follows whichever menu you choose — call the venue or check the menu page for the exact figure per set.

Drinks are estimated per head. The figure the venue uses when budgeting for 35 guests is around 1,000,000đ. That is an estimate, not a fixed charge — a group that drinks less pays less.

Step 4: multiply the total by 1.155

Add the three parts, then multiply once:

(1,500,000đ + set menu + 1,000,000đ) × 1.155

For the room rate alone, the final figure is 1,500,000đ × 1.155 = 1,732,500đ.

Three places people get it wrong

Adding tax first, discounting after. That order gives a higher figure than reality. The venue discounts first and adds tax after.

Applying the percentage to the whole bill. The discount sits only in the room rate. Against the total bill, the real saving usually lands somewhere between 6% and 12% depending on age and room class.

Forgetting drinks. This is the line most often left out of a mental estimate, and the one that shifts the final number most.

Faster than doing it yourself

Call 0915.03.1111 with the guest count, date, time slot and the birthday guest's age. The venue runs both offers and quotes one all-inclusive figure with the better one already applied.