Singapore · Salary, Tax & Money
GST and Service Charge Calculator
Enter a menu price and the calculator adds service charge and then GST in the correct order. Or enter a bill total and it works backwards to the price before charges.
How do you calculate GST and service charge in Singapore?
Apply the service charge to the menu price first, then apply GST to the menu price plus the service charge. With 10% service and 9% GST the combined multiplier is 1.10 × 1.09 = 1.199, so a $100 dish costs $119.90 — not $119, because GST is charged on the service charge as well.
How to use this calculator
- Enter the menu priceThe figure printed on the menu, before any charges. In Singapore this is often shown with ++ after it, which is exactly what this calculator resolves.
- Check the service charge10% is the convention in full-service restaurants, but it is a business decision rather than a statutory rate. Hawker centres and many casual places do not charge it at all.
- Confirm the GST rateGST is set by IRAS and has moved in recent years. The field is editable so the tool does not go stale between changes.
- Or work backwardsSwitch the direction and enter a bill total to find the menu price it came from — useful when you are splitting a bill or checking a receipt.
How the calculation works
The order is not arbitrary and it is not interchangeable. Service charge is applied to the menu price, producing a subtotal. GST is then applied to that subtotal — which includes the service charge.
That means GST is being charged on the service charge as well as on the food. With 10% service and 9% GST, the combined effect is 1.10 × 1.09, which is 1.199. A $100 dish costs $119.90.
Most people add the two percentages and expect $119. The 90 cents difference on a single dish looks trivial; on a $400 table bill it is $3.60, and across a year of business dining it is a real number. More importantly, if you are the one setting menu prices, applying the percentages additively rather than sequentially systematically understates your own bill totals.
Working backwards uses the same logic in reverse. Divide the total by 1.199 to recover the menu price — do not subtract 19%, which is the mirror image of the same error and gives a materially different answer.
total = price × (1 + service charge) × (1 + GST)Worked example: a table for four
Four mains and two bottles of water come to $186 on the menu.
Service charge at 10% adds $18.60, giving a subtotal of $204.60. GST at 9% applies to that subtotal, adding $18.41. The bill is $223.01.
Had you estimated by adding 19% to $186, you would have expected $221.34 — $1.67 low. The gap is precisely the GST charged on the $18.60 of service charge.
Now reverse it. If the receipt says $223.01 and you want to know the menu total, divide by 1.199 rather than subtracting 19%. Dividing gives $186.00 exactly. Subtracting 19% would give $180.64, which is $5.36 out — a much larger error, because you would be taking the percentage off the bigger number.
What ++ actually means
| Notation | What it means | $100 becomes |
|---|---|---|
| $100 | Nett — the price you pay, all charges included | $100.00 |
| $100+ | Subject to GST only | $109.00 at 9% GST |
| $100++ | Subject to service charge and GST | $119.90 at 10% and 9% |
| $100 nett | Explicitly all-inclusive | $100.00 |
The ++ convention is standard across Singapore hospitality and is genuinely useful once you know it — it means the printed price is the base and both charges will be added. A single + means GST only, which is common where no table service is provided.
Who charges what
Service charge is discretionary. There is no law requiring it and no law setting it at 10 per cent — that is simply the industry convention in full-service restaurants and hotels. Hawker centres, food courts and most casual counter-service outlets do not levy it.
It is also not a tip in the sense the word is used elsewhere. Service charge is revenue to the business, distributed according to the business's own policy, and tipping on top is not expected in Singapore.
GST is different. It is a statutory tax set by IRAS, and it applies to supplies made by GST-registered businesses. A small establishment below the registration threshold will not charge it at all, which is why some bills carry service charge but no GST. Where a business is registered, its GST registration number appears on the receipt.
One practical consequence: a price advertised as nett is genuinely the amount you pay, and comparing a nett price against a ++ price without doing this arithmetic will make the ++ option look 20 per cent cheaper than it is.
GST is charged on the service charge, but service charge is never charged on GST. The sequence only runs one way, which is why the multiplier is 1.10 × 1.09 rather than anything more complicated.
Assumptions and limitations
- Assumes the conventional sequence of service charge first, then GST on the subtotal
- Service charge is a business decision — read the actual rate off the menu
- The GST rate is set by IRAS and changes; confirm the current figure before relying on it
- Does not handle mixed bills where some items are zero-rated or exempt
- Does not account for discounts, vouchers or set-menu pricing applied before or after charges
- This is a calculation aid, not tax advice for a business setting its own prices
Questions people ask about this in Singapore
Is service charge applied before or after GST in Singapore?
Before. Service charge is added to the menu price first, and GST is then charged on the menu price plus the service charge.
That is why 10% service and 9% GST produce a 19.9% uplift rather than 19% — the GST is being charged on the service charge as well as on the food.
What does ++ mean on a Singapore menu?
That the printed price is subject to both service charge and GST. A single + means GST only. A price marked nett is all-inclusive and is the amount you actually pay. Comparing a nett price against a ++ price without doing the arithmetic makes the ++ option look about 20% cheaper than it is.
Is service charge compulsory in Singapore?
No. It is an industry convention in full-service restaurants and hotels, typically 10%, but there is no law requiring it or setting the rate. Hawker centres and most counter-service outlets do not charge it at all.
Do I still tip if service charge is added?
Tipping is not expected in Singapore, and service charge is not a tip in the usual sense — it is revenue to the business, distributed under the business's own policy. Additional tipping is uncommon and not anticipated.
How do I work backwards from a bill total to the menu price?
Divide the total by the combined multiplier, which is 1.10 × 1.09 = 1.199 at 10% service and 9% GST. Do not subtract 19% — that takes the percentage off the larger figure and gives a noticeably wrong answer.
Why does my bill have service charge but no GST?
Because the business is not GST-registered. Registration is required above a turnover threshold set by IRAS; smaller establishments below it do not charge GST. A registered business shows its GST registration number on the receipt.
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Method, source and review date
- How it is worked out
- Sequential application of service charge then GST, per standard Singapore billing practice
- Formula used
total = menu price × (1 + service charge) × (1 + GST)- Checked against
- IRAS
- Rates last verified
- Confidence
- Medium
The GST rate is set by IRAS and has changed in recent years, and service charge is a business decision rather than a statutory rate. Both are editable — check the current GST rate against IRAS and read the service charge off the menu.
Spotted a figure that has moved, or a formula you can show is wrong? Tell us — send a correction. Fixes to rates and formulas are treated as urgent.
Disclaimer
This is an estimate only and not tax advice. Tax depends on your full circumstances, and the rules change. Confirm anything that affects a return or a payment with a qualified tax adviser or the tax authority named above.