GST Calculator
Add GST to an amount or remove GST from a GST-inclusive price using any tax rate.
Enter an amount and GST rate to calculate the GST-inclusive total.
How to calculate GST
To add GST, multiply the original amount by the GST percentage and divide by 100.
How to remove GST from an inclusive amount
If the price already includes GST, divide the inclusive amount by one plus the GST rate expressed as a decimal.
GST example
Suppose the original price is 1,000 and the GST rate is 18%.
GST amount = 1,000 × 18 ÷ 100 = 180
Final amount = 1,000 + 180 = 1,180
Final price including GST: 1,180
CGST and SGST example
For an intra-state transaction where GST is split equally between CGST and SGST, each component is half of the total GST amount.
Total GST: 180
CGST: 90
SGST: 90
FAQ
Frequently asked questions
How do I add GST to a price?
Multiply the original price by the GST rate and divide by 100. Add the resulting GST amount to the original price.
How do I remove GST from a price?
Divide the GST-inclusive price by one plus the GST rate expressed as a decimal. The result is the amount before GST.
What is 18% GST on 1,000?
18% of 1,000 is 180, so the total price including GST is 1,180.
Can I use a custom GST rate?
Yes. Enter any percentage in the GST rate field instead of using one of the preset buttons.