GST Calculation: How to Add and Remove GST from Prices

The Two GST Calculations You Need to Know

Adding GST to a base price: Total = Base Price × (1 + GST Rate ÷ 100)

Removing GST from an inclusive price: Base Price = Inclusive Price ÷ (1 + GST Rate ÷ 100)

Adding GST: Examples

Base price Rs 10,000, GST 18%:

GST amount = 10,000 × 0.18 = Rs 1,800

Total payable = 10,000 + 1,800 = Rs 11,800

Or directly: Total = 10,000 × 1.18 = Rs 11,800

GST Rate

Multiply Base By

|---|---|

5%	1.05
12%	1.12
18%	1.18
28%	1.28

Removing GST: Back-Calculating Base Price

You paid Rs 5,900 inclusive of 18% GST. What is the base price?

Base = 5,900 ÷ 1.18 = Rs 5,000

GST amount = 5,900 - 5,000 = Rs 900

CGST + SGST vs IGST

For sales within the same state (intra-state):

CGST = GST Rate ÷ 2 (goes to central government)

SGST = GST Rate ÷ 2 (goes to state government)

Example: 18% GST on Rs 10,000 within Maharashtra:

CGST 9% = Rs 900 + SGST 9% = Rs 900 = Total GST Rs 1,800

For sales across state borders (inter-state):

IGST = Full GST Rate (central government collects and shares with destination state)

Example: 18% GST on Rs 10,000 from Maharashtra to Delhi:

IGST 18% = Rs 1,800

GST Rates at a Glance

0%: Fresh vegetables, milk, eggs, books, newspapers, unbranded atta/maida

5%: Packed food, economy hotels, transport services, tea, edible oils

12%: Processed food, business hotels, non-AC restaurants

18%: Electronics, IT services, banking, mobile phones, AC restaurants

28%: Cars, tobacco, cement, luxury goods, casinos