Reverse GST Calculation Guide

Complete guide on backwards GST calculation

%

Result

GST Calculation
Amount with GST0

SGST Amount0

CGST Amount0
Amount without GST0

Frequently asked questions

Reverse GST Calculation Guide

What is Reverse GST Calculation?

Reverse GST calculation is the process of finding the original price and GST amount when you only know the total amount (which includes GST). It's called "reverse" because you're working backwards from the final amount.

Universal Reverse GST Formula

Amount without GST = Total Amount ÷ (1 + GST Rate/100)

GST Amount = Total Amount - Amount without GST

Quick Division Factors

5% GST

÷ 1.05

12% GST

÷ 1.12

18% GST

÷ 1.18

28% GST

÷ 1.28

Step-by-Step Reverse Calculation

Example: ₹23,600 total amount with 18% GST

1

Identify the total amount: ₹23,600

This includes 18% GST

2

Apply the formula: ₹23,600 ÷ 1.18

1.18 = 1 + (18/100)

3

Calculate base amount: ₹20,000

This is the price before GST

4

Find GST amount: ₹23,600 - ₹20,000 = ₹3,600

This is the 18% GST amount

Common Business Scenarios

Invoice Verification

Check if the GST amount on invoices is calculated correctly by working backwards from the total

Price Comparison

Compare actual product/service costs by excluding GST from different suppliers

Expense Tracking

Separate business expenses from tax amounts for accounting and tax filing

Margin Calculation

Calculate profit margins on the actual selling price excluding GST

⚠️ Important Notes

  • • Always confirm the GST rate applicable to your item/service
  • • Some items may have different GST rates (0%, 5%, 12%, 18%, 28%)
  • • Reverse calculation helps in price negotiations and cost analysis
  • • Use this method to verify GST calculations on bills and invoices

Disclaimer

I am a Software Professional; not a Chartered Accountant.

This tax calculator has been created with the information available to me. I do not claim this to be 100% accurate.

This tax calculator can be used for tax planning to calculate the approximate tax payable by salaried individuals. This should NOT be used to compute the actual taxes to be paid to the Government. I am not resposible for any inaccuracies in the tax computed by this calculator.

If you find any inaccuracy or error, please let me know at the feedback form and I will try to fix it at the earliest.