Singapore GST calculator

The GST rate in Singapore is 9% from 1 January 2024. $100 before GST is $109 with GST. The GST included in a price is the price × 9/109, so a price of $90 includes $7.43 of GST.

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The amount entered

Result

Please complete the details. The result will appear here.

How it is calculated

  1. Adding GST: GST = amount × 9%. Price including GST = amount + GST.
  2. Finding the GST in a price that includes GST: GST = price × 9/109 (the tax fraction). Price before GST = price − GST.
  3. GST is rounded to the nearest cent.
  4. All calculations are done in your browser. The details you enter are not sent to any server.

Worked examples

Add 9% GST to $100

Details
$100.00 Excludes GST (add GST)
Result
Before GST $100.00; GST $9.00; including GST $109.00

Find the GST in $109

Details
$109.00 Includes GST (find the GST)
Result
Before GST $100.00; GST $9.00; including GST $109.00

GST in a price of $90 (IRAS example)

Details
$90.00 Includes GST (find the GST)
Result
Before GST $82.57; GST $7.43; including GST $90.00

Add 9% GST to $19.99

Details
$19.99 Excludes GST (add GST)
Result
Before GST $19.99; GST $1.80; including GST $21.79

Official sources

Applies to: Rate in force from 1 January 2024.

  1. Inland Revenue Authority of Singapore: Current GST rates
  2. Inland Revenue Authority of Singapore: Displaying and quoting prices
  3. Inland Revenue Authority of Singapore: Invoicing customers

Last reviewed on 27 October 2026.

The rules on this page have been checked against the official sources listed above. The result is for reference. The rules and assessment of the concerned authority shall prevail.