Free online calculator
GST Calculator
Add GST to a base amount or extract GST from a GST-inclusive amount.
Free calculator
GST Calculator
Enter your values to see the result.
Formula explained
Add: GST = base × rate. Extract: taxable value = inclusive amount ÷ (1 + rate).
Worked example
₹1,000 plus 18% GST gives ₹180 GST and ₹1,180 total.
Limitations and assumptions
This arithmetic tool does not determine HSN/SAC classification, place of supply, exemptions, ITC eligibility or return-filing treatment.