ArthaSiddhi
GST Calculator
Add GST to a taxable value or separate it from a GST-inclusive amount.
Inputs and assumptions
Enter the applicable rate. Presets are not a complete rate list and do not determine HSN/SAC classification.
GST calculation
Values are rounded only when shown on this page.
Taxable value
₹1,00,000.00
GST rate
18%
CGST
₹9,000.00
SGST
₹9,000.00
IGST
₹0.00
Total GST
₹18,000.00
Invoice total
₹1,18,000.00
GST of ₹18,000.00 takes the taxable value of ₹1,00,000.00 to an invoice total of ₹1,18,000.00.
Rules & assumptions
- Rule period
- Rules verified 16 August 2026
- Last verified
- 2026-08-16
Official sources
- GST goods and services ratesCentral Board of Indirect Taxes and Customs
Based on the cited official material; verify current rules before making an actual decision.
How GST is added or removed
For GST-exclusive amounts, GST is added to the taxable value. For GST-inclusive amounts, the taxable value is derived by dividing the total by 1 + GST rate. Intra-state GST is split equally into CGST and SGST; inter-state GST is shown as IGST.
Important limitations
- Cess, special valuation situations, place-of-supply analysis, and return filing are outside scope.
- Transaction value and place-of-supply rules can affect actual tax treatment; this calculator performs arithmetic only.
Read the Financial Disclaimer.
Guides for this calculator
Main guide
GST Explained: Base Amount, Tax and Total Price
Understand GST-exclusive and GST-inclusive arithmetic, selected rates, tax components, invoice totals and calculator limits.
Related guide
How to Remove GST From an Inclusive Price
Recover the taxable base and GST portion from an inclusive amount using the GST calculator's reverse-GST arithmetic.
Related guide
Why a GST Calculator May Differ From an Invoice
Understand why selected rates, taxable-value rules, line items, rounding and invoice-specific adjustments can produce different GST amounts.