GST Calculation Explained " CGST, SGST & IGST (2026)
GST (Goods and Services Tax) replaced India's complex multi-tax system in 2017. Yet many business owners and consumers still struggle with the question: how do I actually calculate GST? This guide explains exactly how CGST, SGST, and IGST work, with simple formulas and real examples. By the end, you'll be able to add or remove GST from any price in seconds.
→ Use Free GST Calculator India " Instant Result
What is GST?
GST is a destination-based indirect tax levied at every stage of the supply chain. It has replaced Central Excise, Service Tax, VAT, and several other state-level taxes. GST has five rate slabs: 0%, 5%, 12%, 18%, and 28%.
CGST vs SGST vs IGST " The Difference Explained
| Type | Full Form | When Applied | Who Gets It |
|---|---|---|---|
| CGST | Central GST | Intra-state sales | Central Government (half the rate) |
| SGST | State GST | Intra-state sales | State Government (half the rate) |
| IGST | Integrated GST | Inter-state sales | Central Govt (then distributed) |
GST Calculation Formula
Final Price = Price + GST Amount
Removing GST: Original Price = GST-inclusive Price — 100 (100 + GST%)
Step-by-Step Example
Scenario: A trader in Mumbai sells goods worth 50,000 to a buyer in Mumbai (intra-state). GST rate = 18%.
CGST = 50,000 — 9% = 4,500
SGST = 50,000 — 9% = 4,500
Total GST (CGST + SGST) = 9,000
Invoice Total = 50,000 + 9,000 = 59,000
Inter-state sale (same goods, sold to Delhi buyer):
IGST = 50,000 — 18% = 9,000
Invoice Total = 59,000 (same amount, different tax structure)
GST Slabs & Common Items
- 0% " Fresh vegetables, milk, eggs, bread
- 5% " Packed food, economy hotels, rail tickets
- 12% " Butter, cheese, fruit juices, mobile phones
- 18% " Restaurants, financial services, electronics, IT services
- 28% " Luxury cars, tobacco, aerated drinks, casinos
Use Our Free GST Calculator
GST Calculator India " Free & Instant
Enter price and select GST rate. Get CGST, SGST, IGST breakdown instantly. Works for all slabs.
Open GST Calculator →For business finance planning, also use our EMI Calculator for loan installment calculations.
FAQs
Is GST charged on GST?
No. GST is always calculated on the base price excluding GST " it is never charged on another tax.
What is the GST rate on services?
Most services attract 18% GST. However, healthcare and education are exempt (0%), and some services attract 5% or 12%.
How to reverse-calculate (remove) GST?
Original Price = GST-Inclusive Price — 100 / (100 + GST%). For example: 118 with 18% GST → Original = 118 — 100/118 = 100.