GST Calculator
Add GST to a price or extract it from a GST-inclusive amount, with the exact CGST, SGST and IGST breakup. Then create the invoice.
Same state = CGST + SGST. Different state = IGST.
How to calculate GST
To add GST, multiply the base amount by the GST rate and add it back: 18% GST on Rs 10,000 is Rs 1,800, so the total is Rs 11,800. To remove GST from a price that already includes it (a reverse GST calculation), divide the total by one plus the rate: Rs 11,800 divided by 1.18 gives a base of Rs 10,000 and GST of Rs 1,800. The calculator above does both, and shows whether the tax splits into CGST and SGST or is charged as IGST.
GST rates in India
GST is charged in four main slabs. Most services fall under 18%. Always confirm the correct rate for your specific goods or service, since rates are set by the GST Council and revised from time to time.
| Rate | Common examples |
|---|---|
| 5% | Essential items, small restaurants, transport |
| 12% | Processed food, business-class travel, some services |
| 18% | Most services, electronics, standard goods |
| 28% | Luxury and sin goods, large appliances |
CGST, SGST and IGST explained
Which tax applies depends on where the buyer and seller are. When both are in the same state, GST is split equally into CGST (collected by the centre) and SGST (collected by the state). When they are in different states, the whole amount is charged as IGST (integrated GST). The total tax you pay is identical either way; only the split and who collects it change. This is why your invoice shows either a CGST plus SGST line or a single IGST line.
| Supply | Tax charged | Example on 18% |
|---|---|---|
| Within the same state | CGST 9% + SGST 9% | Rs 900 + Rs 900 |
| Between two states | IGST 18% | Rs 1,800 |
Who uses a GST calculator
Shop owners and retailers use it to price goods correctly and to work out how much of a bill is tax. Freelancers and consultants use it to add 18% to their fees. Buyers use the reverse calculation to see the base value of a GST-inclusive purchase, which matters for input tax credit. Accountants use it to check invoice totals quickly. In each case the next step is the same: once you have the numbers, create a GST invoice that shows the CGST, SGST or IGST split correctly.
From calculation to invoice
Knowing the tax is only half the job. A valid GST tax invoice must also carry your GSTIN, an invoice number, the HSN or SAC code and the buyer details. Read the GST invoice format guide for the full list of mandatory fields, use the invoice number generator to set up a clean numbering series, and the rupees in words converter to spell the total for the invoice.
Frequently asked questions
How do I calculate GST on an amount?
To add GST, multiply the base amount by the GST rate. For example, 18% GST on Rs 10,000 is Rs 1,800, giving a total of Rs 11,800. To remove GST from a GST-inclusive amount, divide the total by (1 + rate). The calculator does both instantly.
How do I remove GST from a total (reverse GST)?
Divide the GST-inclusive amount by 1 plus the rate. For 18%, divide by 1.18. So Rs 11,800 inclusive gives a base of Rs 10,000 and GST of Rs 1,800. Select the GST inclusive option above to do this.
What is the difference between CGST, SGST and IGST?
For a sale within the same state, GST is split equally into CGST (central) and SGST (state). For a sale between different states, the whole amount is charged as IGST (integrated). The total tax is the same either way.
What are the GST rates in India?
The main GST slabs are 5%, 12%, 18% and 28%, with some goods at 0% or special rates. Most services fall under 18%. Always confirm the correct rate for your specific goods or service.
This is general information, not tax advice. Confirm the applicable GST rate for your goods or service.