GST Calculator
Add or remove GST from any amount. See the base, tax, and total instantly. Free, accurate, and private.
- Base amount
- 1000
- GST
- 180
- Total
- 1180
How to use
- Enter the amount.
- Set the GST rate (e.g. 18) and choose Add or Remove.
- Read the base, tax, and total.
Examples
- Add 18%:
1000 → tax 180, total 1180 - Remove 18%:
1180 → base 1000, tax 180
FAQ
- What is the difference between adding and removing GST?
- Add treats your amount as the pre-tax base and adds GST on top. Remove treats your amount as GST-inclusive and extracts the base and tax from it.
- How is GST removed from an inclusive price?
- Base = amount ÷ (1 + rate/100), then tax = amount − base. For 1180 at 18%, the base is 1000 and the GST is 180.
- Are results rounded?
- Yes, to two decimal places using standard half-up rounding, the convention for currency.