GST Calculator
Add GST to a base price or back out tax from a GST-inclusive total. View CGST/SGST (half each) or IGST for inter-state — quick math only, not filing.
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How GST math works
Add GST: GST = Amount × (rate/100), Total = Amount + GST. Remove GST: If amount includes GST, Taxable = Amount ÷ (1 + rate/100), GST = Amount − Taxable.
For intra-state supplies, CGST and SGST are typically half of the total GST each. For inter-state, IGST equals the full GST rate amount in one component. Actual invoicing must follow your GST registration and HSN/SAC rules — this page is a quick arithmetic aid only.
Frequently asked questions
What is GST?
Goods and Services Tax — an indirect tax on supply; intra-state often uses CGST+SGST, inter-state uses IGST.
Is this official GST filing?
No — it is a calculator only, not connected to the GST portal.
How do I add or remove GST?
Add: GST = amount × rate/100. Remove: taxable = inclusive ÷ (1 + rate/100). See the section below for CGST/SGST vs IGST display.
CGST/SGST vs IGST?
Intra-state shows CGST and SGST (typically half of total GST each). Inter-state shows IGST as the full GST line.
Is my data uploaded?
No — calculations run in your browser.