Reverse GST Calculator
Extract embedded tax values. Input the final gross amount and select standard tax rates to find the pre-tax base value and the tax amount.
Parameters
$
%
Results Summary
Gross Price
$11,800
GST Portion (18%)
$1,800
Net Price
$10,000
Mathematical Formula
This calculator determines the results based on the following standard financial formula for GST Subtraction:
Net Price = Gross Price / (1 + GST Rate / 100)
Variables Glossary
- Net Price
- Base price before adding tax
- Gross Price
- Final price including GST (post-tax)
- GST Rate
- Tax percentage (e.g. 18%)
- GST Amount
- Tax portion extracted
By dividing the gross value by the tax percentage factor, we separate the base net price from the tax component.
Frequently Asked Questions
What is a Reverse GST calculation?
A reverse GST calculation (tax subtraction) extracts the original pre-tax base price of a product when you only know the final tax-inclusive gross amount.
What is the formula to extract base price from a tax-inclusive amount?
To extract the base net price, divide the gross price by (1 + tax rate / 100). Net Price = Gross Price / (1 + GST Rate / 100). The tax portion is the difference between gross and net.