GST Calculator: Add or Remove GST Online
Add GST to a price or extract GST from a GST-inclusive amount with CGST / SGST / IGST split.
GST Calculator
Indicative estimate. Verify with official sources.
GST registration and filing
Calculated your GST? Let GstMan register you, issue compliant invoices and file your returns.
How GST is calculated
Add GST: GST amount = Base × Rate ÷ 100; Total = Base + GST.
Remove GST (reverse GST): Base = Total ÷ (1 + Rate ÷ 100); GST = Total − Base.
Intra-state supplies split GST equally into CGST and SGST/UTGST; inter-state supplies attract IGST.
Choosing the right rate
The rate depends on the HSN/SAC of the supply. India's GST rate structure was rationalised in September 2025 (primarily 5% and 18% with a higher rate for specified goods). Always verify the current rate for your item using the official notification or ask our experts.
GST Calculator FAQs
What is the formula to calculate GST?
GST = Base amount × GST rate ÷ 100. For a GST-inclusive price, Base = Total ÷ (1 + rate ÷ 100).
How do I do reverse GST calculation?
Choose 'Remove GST', enter the GST-inclusive amount and the rate. The tool returns base value, CGST, SGST/IGST.
When is IGST charged instead of CGST and SGST?
IGST applies to inter-state supplies and imports/exports; CGST and SGST apply to intra-state supplies. Place of supply rules decide this.
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