How is GST calculated?

To add GST: amount × (1 + rate). To remove GST from a GST-inclusive price: amount ÷ (1 + rate). At 18%, ₹1,000 becomes ₹1,180 inclusive; ₹1,180 inclusive contains ₹180 GST.

What are the GST slabs in India?

India uses multiple slabs: 0% (essential items), 5% (basic necessities), 12% and 18% (most goods and services), and 28% (luxury items), with cess on top for certain categories. 18% is the most common rate for services.

What is the difference between CGST, SGST, and IGST?

For sales within a state, GST splits equally into CGST (central) and SGST (state) — an 18% rate becomes 9% + 9%. For inter-state sales, the full amount is charged as IGST. This calculator shows the CGST/SGST split automatically.

How do I calculate GST-exclusive price from an inclusive one?

Divide by (1 + rate): a ₹1,180 GST-inclusive invoice at 18% is ₹1,180 ÷ 1.18 = ₹1,000 base + ₹180 tax. Never subtract the percentage directly — it gives the wrong base.

Do other countries use GST?

Yes — Australia (10%), New Zealand (15%), Singapore (9%), Canada (5% federal plus provincial), and Malaysia (SST). The math is identical; only rates and names differ.

GST Calculator — Add or Remove GST with CGST/SGST Split, Fre...

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GST Calculator — Add, Remove, and Split GST Correctly

Whether you're invoicing a client at 18%, checking the tax on a purchase, or splitting CGST and SGST for a return, GST math has one recurring trap: reverse calculation. This free GST calculator adds GST to base prices and correctly extracts GST from inclusive totals (division, not subtraction), showing the base, tax, total, and the intra-state CGST/SGST split — for Indian slabs and any custom rate worldwide. No signup, instant.

Formulas That Never Fail

Add GST: total = base × (1 + rate). ₹1,000 at 18% → ₹1,180.

Remove GST: base = total ÷ (1 + rate). ₹1,180 at 18% → ₹1,000 base, ₹180 GST.

GST from inclusive total directly: GST = total × rate ÷ (100 + rate). ₹1,180 × 18 ÷ 118 = ₹180.

Indian GST Slabs at a Glance

Slab	Typical items	₹1,000 base becomes
0%	Fresh food, essential items	₹1,000
5%	Packaged food, transport	₹1,050
12%	Processed food, some electronics	₹1,120
18%	Most services, software, electronics	₹1,180
28%	Luxury goods, automobiles	₹1,280

CGST + SGST vs IGST

Within one state, GST splits evenly between the centre and the state: an 18% invoice shows CGST 9% + SGST 9%. Across state lines, the full 18% is charged as IGST. The tax burden is identical — only the reporting buckets change — but invoices must show the correct split, which is why this calculator displays it automatically for every calculation.

Practical Uses

Invoicing — quote a base fee and generate the exact GST lines for the bill.
Purchase verification — confirm a vendor charged the right tax on an inclusive price.
Pricing strategy — hit a round inclusive price point (₹999) and know exactly what base and margin remain.
Returns preparation — extract tax components from mixed inclusive receipts.

Free and Instant

All slabs, custom rates, both directions, CGST/SGST breakdown — computed locally in your browser with no account and no limits.

Base amount
Total GST
CGST (half)
SGST (half)
Total (incl. GST)

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