Calculate GST amount and final price — add or remove GST from any amount
GST: total amount (with gst) is ₹11,800, based on the entered inputs.
Formula
GST Amount = Base Price × GST Rate ÷ 100; Total Price = Base Price + GST Amount
Worked example
| Input | Value |
|---|---|
| Amount | ₹10,000 |
| GST Rate | 18% — Most services, electronics |
| Calculation Mode | Add GST (exclusive — amount before GST) |
| Total Amount (with GST) | ₹11,800 |
| GST Amount | ₹1,800 |
| Pre-GST Amount | ₹10,000 |
| CGST (50%) | ₹900 |
| SGST / UTGST (50%) | ₹900 |
| IGST (interstate, 100%) | ₹1,800 |
Adding and removing GST correctly
GST arithmetic trips people in one specific place: removing GST from an inclusive price is not subtracting the rate. Adding 18% to ₹1,000 gives ₹1,180 — but the GST inside ₹1,180 is ₹180, which is 15.25% of the total, not 18%. The calculator handles both directions without the classic error.
Add: price × (1 + rate). Remove: inclusive ÷ (1 + rate) = base; GST = inclusive − base
To extract 18% GST from an inclusive amount, divide by 1.18 — never multiply the inclusive figure by 18%.
ExampleAn invoice shows ₹59,000 inclusive of 18% GST. Base = 59,000 ÷ 1.18 = ₹50,000; GST = ₹9,000. The wrong way (59,000 × 18% = ₹10,620) overstates the tax by ₹1,620 — an error that compounds across every line of a quotation or an input-credit claim.
The common slabs: 0% (essentials), 5% (packaged food, transport), 12% and 18% (most goods and services — 18% covers nearly all professional services), 28% (luxury/sin goods, often plus cess). For businesses, GST paid on inputs is creditable against GST collected — the tax is designed to tax only the value you add.
✓ You learnedDivide by (1+rate) to strip GST out of an inclusive price; multiply by (1+rate) to add it. Quoting “plus GST” vs “inclusive” changes real revenue by the full slab — make every quotation explicit about which it is.
FAQs
What are CGST, SGST and IGST on my invoice?
The same tax, split by geography: an intra-state sale splits the rate into equal CGST (centre) + SGST (state) halves — 9% + 9% for an 18% item — while an inter-state sale charges the full rate as IGST. Your total GST is identical either way; the split only determines which government receives it.