GST Calculator
This free GST calculator online adds GST to any amount and shows the tax amount, the final price, and the CGST/SGST or IGST split. Enter a value, pick a rate, and the result updates instantly — useful for shopkeepers, freelancers and accountants pricing goods or services under the current Indian GST slabs.
How to use this GST calculator
- Enter the base amount (the price before GST).
- Choose a GST rate chip (0%, 5%, 18%, 40%) or type a custom rate.
- Select intra-state (CGST + SGST) or inter-state (IGST).
- Read the GST amount, tax split and total price in the result panel.
GST formula with a worked example
To add GST to a price:
GST amount = Base amount × Rate ÷ 100
Total price = Base amount + GST amount
Example: A shopkeeper sells goods worth ₹1,000 at 18% GST within the same state. GST = 1,000 × 18 ÷ 100 = ₹180. This splits into CGST ₹90 and SGST ₹90. The customer pays ₹1,180. If the buyer were in another state, the ₹180 would be charged as IGST instead.
Current GST slabs (2025)
| Slab | Typical items |
|---|---|
| 0% (Nil) | Fresh produce, unbranded staples, many essential items |
| 5% | Most food products, medicines, essential goods |
| 18% | Standard rate — most goods, electronics, small cars, services |
| 40% | Luxury & sin goods (e.g. aerated drinks, tobacco, large/luxury vehicles) |
Some items keep special rates (for example 3% on gold). Use the custom rate field for these. The 12% and 28% slabs were removed in the September 2025 reform.
FAQ
How do I calculate GST on an amount?
GST amount = base amount × GST rate ÷ 100, and total = base + GST. For ₹1,000 at 18%, GST is ₹180 and total is ₹1,180.
When is GST split into CGST and SGST?
For a sale within the same state (intra-state), GST is split equally into CGST and SGST. For a sale between states (inter-state), the whole GST is charged as IGST.
What GST rates can I use?
The common slabs are 0%, 5%, 18% and 40%. Type any custom rate for special cases such as 3% on gold.
Does this calculator store my data?
No. Everything runs in your browser and nothing is uploaded or saved on any server.
Related tools
Reverse GST
Extract GST from a GST-inclusive price.
Inclusive GST
Two-way inclusive/exclusive converter.
GST Bill Generator
Turn this into a full invoice.
GSTIN Validator
Check a GST number's checksum.
Guide: How to calculate GST
Formulas and examples explained.
Guide: GST rates explained
The 2025 slab changes in detail.
Last updated: 2 July 2026. GST slabs per the 56th GST Council meeting (effective 22 September 2025).