Disclaimer: Estimates only; Singapore’s current GST rate is 9%, but zero-rated or exempt supplies may be treated differently.
What Is a GST Calculator Singapore?
A GST Calculator Singapore helps you add GST to a price or extract GST from a total that already includes it.
The calculator displays:
- GST amount
- Total excluding GST
- Total including GST
You can find more locally focused tools on the Calculator Singapores homepage.
How to Use the Calculator
1. Enter the Amount
Enter the price in Singapore dollars.
The amount must be greater than zero. You can include dollars and cents, such as 125.50.
2. Check the GST Rate
The calculator uses 9% as its default rate.
The rate is editable. This allows you to check an older transaction using the rate that applied at that time.
3. Select the Price Type
Choose Excluding GST if GST has not been added to the entered amount.
Choose Including GST if the amount already contains GST.
For bills containing both GST and a service charge, use the Singapore Service Charge And GST Calculator to apply the two charges in the correct order.
4. Select Calculate
The result shows the GST amount and totals before and after GST.
Select Reset to clear the amount. The calculator will return to a 9% rate and the Excluding GST option.
GST is different from personal income tax and other tax calculations. The Singapore Tax Calculator is useful when you need to explore other common Singapore tax estimates.
Adding and Removing GST Formula
The calculator uses a different formula for each price type.
Adding GST to a Price
When the entered price excludes GST:
GST amount = Price excluding GST × GST rate ÷ 100
Price including GST = Price excluding GST + GST amount
At the current 9% rate:
Price including GST = Price excluding GST × 1.09
Removing GST From an Inclusive Price
When GST is already included:
Price excluding GST = Price including GST ÷ (1 + GST rate ÷ 100)
GST amount = Price including GST − Price excluding GST
At a 9% rate:
Price excluding GST = Price including GST ÷ 1.09
Do not remove GST by subtracting 9% from the final price. The inclusive amount represents 109% of the original price, so it must be divided by 1.09.
One GST Calculation Example
Suppose an item costs S$200 before GST.
The selected rate is 9%, and the price type is Excluding GST.
GST amount = S$200 × 9 ÷ 100
GST amount = S$18
The final price is:
S$200 + S$18 = S$218
The calculator should display:
- GST Amount: S$18
- Total Excluding GST: S$200
- Total Including GST: S$218
If you are checking a gold purchase, first estimate its value with the Gold Price Calculator Singapore. The type of gold can affect its GST treatment, so calculating 9% does not confirm that GST applies.
Current GST Rate in Singapore
Singapore’s current standard GST rate is 9%.
GST-registered businesses generally charge 9% on standard-rated sales of goods and services in Singapore. Certain supplies may be zero-rated, exempt or outside the scope of GST.
Singapore’s recent standard rates were:
- 7% from 1 July 2007 to 31 December 2022
- 8% from 1 January to 31 December 2023
- 9% from 1 January 2024
The current and historical rates are published by IRAS.
Use the rate that applied when the transaction took place.
What the Calculator Cannot Decide
The calculator performs the calculation using the amount, rate and price type entered. It cannot decide whether GST legally applies to a transaction.
The correct treatment may depend on:
- Whether the seller is GST-registered
- The type of goods or services
- Whether the supply is standard-rated
- Whether the supply is zero-rated or exempt
- The transaction date and location
The calculator also cannot check GST registration requirements, input-tax claims, special GST schemes, filing adjustments or refunds. A seller cannot charge GST merely because this calculator produces a GST amount.
GST should also be kept separate from unrelated religious calculations.
The Faraid Calculator Singapore estimates the estate remaining after the entered expenses, debts and religious obligations. It does not calculate GST or determine beneficiaries’ inheritance shares.
No. Fidyah is unrelated to GST. The Fidyah Calculator Singapore estimates fidyah from applicable missed fasting days using the published 2026 rate of S$4 per day.
Displayed Prices and Service Charges
GST-registered businesses generally need to display GST-inclusive prices to the public. If inclusive and exclusive prices are both shown, the inclusive price should be at least as prominent.
Some hotels and food and beverage businesses that impose service charge may display prices subject to GST and service charge when this is clearly stated. Check the menu, invoice, receipt or quotation before selecting the price type.
Common Mistakes and Invoice Differences
Selecting the Wrong Price Type
Choosing Excluding GST for a price that already contains GST adds GST twice. Check how the price is described before calculating.
Using the Wrong Rate
Do not automatically use 9% for an older transaction. Check the date and enter the rate that applied then.
Entering the Final Price as a Pre-GST Price
If the amount is already GST-inclusive, select Including GST. Otherwise, the calculator will treat it as the original pre-tax price.
Differences From an Invoice
A business may calculate GST separately for individual items and then round each amount. This can produce a small difference from calculating GST on one combined total.
Discounts, mixed GST treatment and adding a service charge before GST can also change the invoice amount.
Frequently Asked Questions
Q1: What does the calculator calculate?
A: It calculates the GST amount, price excluding GST and price including GST from the amount and rate entered.
Q2: What is Singapore’s current GST rate?
A: Singapore’s current standard GST rate is 9%. It has applied since 1 January 2024.
Q3: How much is 9% GST on S$100?
A: The GST is S$9. The final GST-inclusive amount is S$109.
Q4: How do I remove GST from an inclusive price?
A: Select Including GST. At a 9% rate, the calculator divides the total by 1.09 to find the pre-GST price.
Q5: Does it include service charge?
A: No. The calculator only adds or extracts GST.
Q6: Why can the result differ from an invoice?
A: Item-level rounding, discounts, mixed GST treatment or a service charge can create a small difference.
Q7: Is the result an official IRAS assessment?
A: No. The result is an estimate based on the entered information and does not replace an official assessment, invoice or GST return.