GST Calculator
GST in India is charged at one of a handful of rates — 0%, 5%, 12%, 18%, 28% or the 40% de-merit slab — depending on the good or service. This calculator does the two things you actually need: add GST to a pre-tax price to get the amount you'll charge or pay, or strip GST out of a tax-inclusive price to see the base and the tax hidden inside it.
Within a single state the tax splits equally into CGST (central) and SGST (state); across states it's a single IGST of the same total. The split is only a matter of which government gets which half — the amount you pay is identical either way.
₹10,000 + 18% GST = ₹11,800. Intra-state that's CGST ₹900 + SGST ₹900; inter-state it's IGST ₹1,800.
How it works
- 01Adding GST: tax = amount × rate, and the total is amount + tax. A ₹10,000 item at 18% becomes ₹11,800.
- 02Removing GST: the sticker price already includes tax, so the base is price ÷ (1 + rate), and the GST is what's left over. ₹11,800 at 18% backs out to ₹10,000 base + ₹1,800 GST.
- 03The GST figure is then halved into CGST + SGST for an intra-state sale; for an inter-state sale the same total is charged once as IGST.
Frequently asked
What's the difference between CGST, SGST and IGST?+
They're the same tax collected differently. On a sale within one state, GST is split into CGST (goes to the centre) and SGST (goes to the state) — each half the total rate. On a sale between states, the whole amount is charged once as IGST. You pay the same total; only the routing differs.
How do I remove GST from a total?+
Divide the inclusive amount by (1 + rate). At 18%, divide by 1.18 to get the base price; the difference is the GST. Switch this calculator to "Remove GST" and it does exactly that.
Which GST rate applies to my product?+
It depends on the HSN/SAC classification. Broadly: essentials and many food items are 0% or 5%, standard goods and most services are 18%, and luxury or "sin" goods (high-end cars, tobacco, aerated drinks) sit in the top 40% de-merit slab. The 12% and 28% rates still apply to some items transitionally. Check the official CBIC rate finder for the exact rate on a specific item.
Is this an official GST tool?+
No — it's a plain arithmetic calculator using the rate you pick. It doesn't look up HSN codes, cess on luxury goods, or input-tax-credit rules. Use it to check a figure, not to file a return.