How to Calculate GST: Adding and Removing Tax
A clear guide on how Goods and Services Tax (GST) is calculated, including formulas to add GST or extract it from a gross price.
Indirect Tax & Commercial Calculation Specialists
What is GST?
The Goods and Services Tax (GST) is an indirect, broad-based consumption tax applied to the cost of most goods and services.
Formula to Add GST
If you have a base price and need to add GST to find the final price:
GST Amount = (Original Cost × GST Rate) / 100 Final Price = Original Cost + GST Amount
Example: Adding 18% GST to ₹1,000
- GST Amount = (1000 × 18) / 100 = ₹180
- Final Price = 1000 + 180 = ₹1,180
Formula to Remove GST (Extracting Base Price)
If you have a final price that already includes GST, and you need to find the original base price:
Original Cost = [Final Price × 100] / [100 + GST Rate]
Example: A product costs ₹1,180 inclusive of 18% GST. What was the base price?
- Base Price = (1180 × 100) / (100 + 18)
- Base Price = 118000 / 118 = ₹1,000
Calculate GST Slabs Online
To instantly toggle between adding tax or extracting base prices across standard brackets (5%, 12%, 18%, 28%), test the free GST Calculator.