Tool
GST Calculator
Add GST to a price or work it back out of a GST-inclusive total, at the rates in force after the September 2025 rationalisation.
- Amount before GST
- —
- GST
- —
- Total amount
- —
Both directions#
A Indian GST calculation runs one of two ways, and getting the direction wrong is the most common error on an invoice.
Adding GST to a pre-tax price:
GST = amount × rate ÷ 100
Extracting GST from a price that already includes it — a retail MRP, a restaurant bill, a receipt you are reconciling:
Amount before GST = total × 100 ÷ (100 + rate)
The second is not the first run backwards. Taking 18% off ₹11,800 gives ₹9,676, which is wrong. Dividing by 1.18 gives ₹10,000, which is right. On a ₹11,800 invoice the two methods differ by ₹324, and that error compounds across a quarter of bookkeeping.
The rates, after September 2025#
The 56th GST Council meeting rationalised the structure with effect from 22 September 2025, collapsing four main slabs into two.
| Rate | Applies to |
|---|---|
| 0% | Fresh produce, basic medicines, educational materials |
| 0.25% | Rough and industrial diamonds |
| 3% | Gold, silver, platinum and gemstones |
| 5% | Essentials and daily-use goods |
| 18% | The standard rate for most goods and services |
| 28% | Tobacco and pan masala |
| 40% | Luxury and sin goods |
The 12% slab is gone. Items that sat in it moved either down to 5% or up to 18%. It remains in the dropdown above only because invoices raised before 22 September 2025 still need reconciling.
CGST, SGST and IGST#
The calculator shows one GST figure because that is the total you pay. How it splits depends on where the supplier and the buyer are:
- Within one state — the amount divides equally into CGST and SGST. An 18% supply is 9% CGST plus 9% SGST.
- Across states, or on imports — the whole amount is IGST, collected by the centre and apportioned later.
The total is identical either way. The split matters for your returns and your input tax credit, not for the price.
What this does not include#
Cess. Certain goods carry a compensation cess on top of GST. Where it applies, add it separately.
Reverse charge. On some supplies the recipient pays GST directly rather than the supplier collecting it. The amount is the same; the person remitting it is not.
Composition scheme. Small suppliers under the composition scheme pay a flat percentage of turnover and cannot charge GST on their invoices at all.
Questions#
Is the MRP inclusive of GST?#
Yes. Maximum retail price is the all-in price by law, so any GST is already inside it. Use the "After GST" option to see what the pre-tax price was.
Why does my restaurant bill show 5% when the standard rate is 18%?#
Restaurant services are rated separately from goods, and most stand-alone restaurants charge 5% without input tax credit. Establishments inside hotels above a room-tariff threshold charge 18%.
Do I charge GST if I am under the registration threshold?#
No — you cannot charge it without a registration, and you cannot claim input credit either. The threshold is turnover-based and differs for goods, services and for special category states.