Home Guides & Blog GST Calculator: CGST, SGST & IGST Explained 2026

GST Calculator: CGST, SGST & IGST Explained 2026

Table of Contents
  1. GST Rate Slabs
  2. CGST vs SGST vs IGST
  3. Example: 18% GST on ₹1,000
  4. Reverse GST Calculation
  5. Input Tax Credit
  6. GST Registration Threshold

GST Rate Slabs

India uses: 0% (essentials), 3% (gold), 5% (basic), 12% (processed food), 18% (most services), 28% (luxury).

CGST vs SGST vs IGST

Intra-state: CGST + SGST = total GST rate (split equally). Inter-state: IGST at full rate.

Example: 18% GST on ₹1,000

  • Intra-state: CGST ₹90 + SGST ₹90 = ₹180
  • Inter-state: IGST = ₹180
  • Total invoice: ₹1,180

Reverse GST Calculation

Pre-GST = Price × 100 / (100 + GST%). Example: ₹1,180 at 18% = ₹1,000 base price.

Input Tax Credit

Registered businesses can claim ITC on purchases against output GST liability, avoiding cascading taxes.

GST Registration Threshold

Mandatory if annual turnover exceeds ₹40 lakhs (goods) or ₹20 lakhs (services). Also required for inter-state sales and e-commerce.

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Disclaimer: This article is for informational purposes only and does not constitute financial or tax advice. Tax laws and rates may change. Consult a qualified chartered accountant or financial advisor for decisions specific to your situation.

Need a correction? Contact us if you spot an outdated rule, unclear explanation, or factual error.

Last updated: Jan 2026

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