By MoneyBees
Add 9% GST to a price or take it out of a GST-inclusive price, work out a restaurant bill with service charge, and total an invoice both ways IRAS allows. Switch to the 8% or 7% rate for older invoices.
Use the rate in force when the sale was made.
Before GST
$100.00
GST at 9%
$9.00
9% of $100.00
With GST
$109.00
cash bill rounded down: $109.00
| Rate | In force | GST | With GST |
|---|---|---|---|
| 9% | 2024-01-01 to today | $9.00 | $109.00 |
| 8% | 2023-01-01 to 2023-12-31 | $8.00 | $108.00 |
| 7% | 2007-07-01 to 2022-12-31 | $7.00 | $107.00 |
| 5% | 2004-01-01 to 2007-06-30 | $5.00 | $105.00 |
| 4% | 2003-01-01 to 2003-12-31 | $4.00 | $104.00 |
| 3% | 1994-04-01 to 2002-12-31 | $3.00 | $103.00 |
Rate periods from IRAS. GST began on 1 Apr 1994.
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A stationery shop sells three pens at S$1.28 each before GST. Taxed one line at a time, each pen carries S$0.12 GST (S$0.1152 rounded), so the GST is S$0.36 and the bill is S$4.20. Taxed on the S$3.84 subtotal, the GST is S$0.3456, rounded to S$0.35, and the bill is S$4.19. Both are IRAS's own figures and both are allowed.
A S$100 dinner with a 10% service charge costs S$110 before GST. GST at 9% is S$9.90, so you pay S$119.90.
Figures checked 3 Oct 2026.
9%. It has applied since 1 January 2024. It was 8% in 2023 and 7% from 1 July 2007 to 31 December 2022. GST started at 3% on 1 April 1994.
Multiply the price before GST by 1.09. The GST on its own is the price times 9%. S$100 before GST is S$109 with GST, and the GST is S$9.
Multiply the GST-inclusive price by 9/109. That is the GST. Take it away from the price to get the amount before GST. On S$109 the GST is S$9. On S$90 it is S$7.43.
IRAS lets a business either work out 9% on each line and add the lines up, or work out 9% once on the subtotal, and rounding makes the two differ by a cent or so. Both are allowed as long as the business uses the same method every time.
The total GST is rounded to the nearest cent. A business may also round the whole bill to the nearest 5 cents for cash payments, up or down, as long as it does the same every time.
Yes, GST is charged on the food and on the service charge. A S$100 meal with a 10% service charge comes to S$110 before GST, and 9% GST on that is S$9.90, so the bill is S$119.90.
Yes, if they are GST-registered. Price tags, adverts and websites must show the GST-inclusive price. Hotels and restaurants that add a service charge may show prices before GST if they say clearly that GST and service charge apply.
When its taxable turnover is more than S$1 million. Businesses below that can choose to register.
The calculator works in cents and rounds GST to the nearest cent, with half a cent going up. For a cash bill, a business may also round the total to the nearest 5 cents, as long as it does it the same way every time. The result tile shows the total rounded down to 5 cents.
These calculators provide general estimates for educational purposes only and are not personalised financial advice. Results may rely on rates and rules that change over time, so verify against official sources (IRAS, CPF Board, HDB, MAS) or consult a licensed financial adviser before making decisions.
Junxiong-WFG Organisation is an authorised representative of AIA Financial Advisers Private Limited (Reg. No. 201715016G).