Tax & Compliance
6 min read
•Updated 2026-09-17
How GST is Calculated: Inclusive vs Exclusive Pricing & Tax Invoice Formulas
A complete merchant and consumer reference for computing reverse GST, base prices, and intra-state tax splits.
By AnyCalcHub Tax & Compliance Desk
Live Interactive Tool
Calculate Your Own Numbers Instantly
Run this calculation in your browser with real-time graphs and auto-save.
1. GST Exclusive vs GST Inclusive Formulas
Depending on whether the sticker price includes or excludes tax, different formulas apply.
Mathematical Formula
GST Amount (Exclusive) = (Base Price × GST Rate) / 100 Base Price (Inclusive) = Total Price / (1 + GST Rate / 100) GST Amount (Inclusive) = Total Price - Base Price
Step-by-Step Worked Example
Total Inclusive Price₹1,180
GST Rate18%
Step 1:Divide total by 1.18: 1,180 ÷ 1.18 = ₹1,000 base price
Step 2:Subtract base from total: 1,180 - 1,000 = ₹180 GST
Final Result: Base Price: ₹1,000 | CGST (9%): ₹90 | SGST (9%): ₹90
Frequently Asked Questions
Common questions and mathematical nuances for this calculation.
When is IGST charged instead of CGST and SGST?
IGST (Integrated GST) applies to inter-state supplies (when buyer and supplier are located in different states). For intra-state transactions within the same state, tax is split equally between CGST (Central) and SGST (State).
Try the Calculator
Launch CalculatorReady to calculate your own results?
Launch GST Calculator with real-time sliders and instant graphs.
Related Calculation Guides
Mathematics