GST Calculator
Add GST to a price or remove it from a GST-inclusive amount, with the CGST, SGST and IGST split.
Final price
Within one state (intra-state)
Between states (inter-state)
On an intra-state supply, GST is normally split equally between CGST and SGST. CGST is rounded to the paisa and SGST is the rest, so the two always add up to the GST amount.
How it works
To add GST to a price before tax:
GST = Price × Rate ÷ 100 · Final price = Price + GST
To remove GST from a GST-inclusive price:
Price before GST = Inclusive price × 100 ÷ (100 + Rate) · GST = Inclusive price − Price before GST
Then the GST is shown two ways:
- Intra-state (seller and place of supply in the same state): normally split equally between CGST and SGST. CGST = GST ÷ 2, rounded to the paisa; SGST = GST − CGST.
- Inter-state (different states): IGST = GST
The rate is whatever you enter; the calculator does not decide which rate applies. GST is rounded to the paisa, and the price before GST is rounded so that price + GST matches the inclusive price exactly.
Worked example
Adding GST: a price of ₹2,499 before GST, at 18%.
- GST = ₹2,499 × 18 ÷ 100 = ₹449.82
- Final price = ₹2,499 + ₹449.82 = ₹2,948.82
- Intra-state: CGST ₹224.91 + SGST ₹224.91. Inter-state: IGST ₹449.82
Removing GST: a GST-inclusive price of ₹999, at 18%.
- Price before GST = ₹999 × 100 ÷ 118 = 846.6102, rounded to₹846.61
- GST = ₹999 − ₹846.61 = ₹152.39
- Intra-state: CGST = ₹152.39 ÷ 2 = 76.195, rounded to₹76.20; SGST = ₹152.39 − ₹76.20 =₹76.19. Inter-state: IGST ₹152.39
Frequently asked questions
How do I add GST to a price?
Multiply the price before GST by the GST rate and divide by 100 to get the GST amount, then add it to the price. For example, ₹1,000 at 18% has GST of ₹1,000 × 18 ÷ 100 = ₹180, so the final price is ₹1,180.
How do I remove GST from a price that already includes it?
Divide the GST-inclusive price by (100 + rate) and multiply by 100 to get the price before GST. The difference is the GST. For example, ₹1,180 at 18% gives ₹1,180 × 100 ÷ 118 = ₹1,000 before GST, and ₹180 of GST.
Why can't I just subtract 18% from a GST-inclusive price?
Because GST is charged on the price before tax, not on the final price. Taking 18% off ₹1,180 gives ₹967.60, which is wrong. The correct price before GST is ₹1,000, found by dividing by 1.18.
What are CGST, SGST and IGST?
India uses a dual GST. On a supply within one state (intra-state), the Centre levies Central GST (CGST) and the state levies State GST (SGST). On a supply from one state to another (inter-state), the Centre levies Integrated GST (IGST), which is CGST plus SGST. On an intra-state supply, GST is normally split equally between CGST and SGST; this calculator shows that split, and the inter-state amount as IGST.
What is UTGST?
In union territories without a legislature, State GST is called Union Territory GST (UTGST). On an intra-state supply there, you see CGST and UTGST instead of CGST and SGST.
Which GST rate applies to my product or service?
GST rates are set by law for each type of goods or service and can change. This calculator does not list or suggest rates. Check the GST rate for your product on the official GST portal or your supplier's tax invoice, or ask a tax professional, and enter it above.
Does this calculator include cess or round the figures?
No cess is included. Some goods may attract a cess in addition to GST; add it separately if it applies to you. Figures are rounded to the paisa, with CGST rounded and SGST taking the remainder so the parts add up exactly. Invoices may round differently, so small differences of a paisa or so are normal.