Free calculator
GST calculator
Enter a price and choose whether to add GST or take it out. You get the price excluding GST, the GST and the total your tax invoice will show.
GST
$90.00
- Price excluding GST
- $1,000.00
- GST at 9%
- $90.00
- Total including GST
- $1,090.00
How GST is worked out
GST is 9% of the price excluding GST. On S$1,000 the GST is S$90 and the total S$1,090.
To take GST out of a price that includes it, multiply by 9/109: S$1,090 includes S$90 of GST. That works only when the whole price is standard-rated.
Round GST to the nearest cent. A tax invoice shows the total excluding GST, the GST rate, the GST and the total including GST.
When you charge GST
- Only once you’re registered for GST — compulsory when your taxable sales pass S$1 million in a calendar year, or you expect them to in the next 12 months.
- At 0% on exported goods and international services that qualify under section 21(3).
- Not at all on exempt supplies, such as financial services and residential property.
Last updated . This calculator is a guide, not tax advice.
Frequently asked questions
How do I calculate GST from a total in Singapore?
Multiply the GST-inclusive total by 9 and divide by 109. S$218 includes S$18 of GST, so the price excluding GST is S$200.
Do I charge GST if I’m not registered?
No. Until IRAS registers you, your invoices show no GST and mustn’t be titled “Tax Invoice”. Most freelancers and small businesses are below the S$1 million threshold.
Is GST still 9%?
Yes. GST has been 9% since 1 January 2024.