GST Calculator: How to Add or Remove GST (CGST & SGST)

GST (Goods and Services Tax) is added to most goods and services in India. A GST calculator helps you quickly add GST to a base price, or work backwards to find the base price from a GST-inclusive amount.

Common GST rates in India

The main GST slabs are 5%, 12%, 18% and 28%. Different products and services fall under different slabs. Always confirm the correct rate for your item.

How to add GST

GST amount = base price × rate / 100. Total = base price + GST. For example, ₹1,000 + 18% GST = ₹180 GST, so the total is ₹1,180.

How to remove GST (reverse calculation)

If a price already includes GST, base price = total / (1 + rate/100). For example, ₹1,180 at 18% gives a base of ₹1,000 and ₹180 GST.

What are CGST and SGST?

For sales within the same state, the total GST is split equally into CGST (Central) and SGST (State). So 18% becomes 9% CGST + 9% SGST. For sales between states, the same total is charged as IGST instead.

How to use our free GST calculator

1. Open the GST calculator.
2. Choose Add GST or Remove GST.
3. Enter the amount and pick the GST rate.
4. Click Calculate to see the base, GST, CGST/SGST split and total.