GST Calculator
Add GST to a price, or remove it from a GST-inclusive total.
Choose your country preset or enter a custom rate. Results show the base amount, tax component, and final price — including the CGST/SGST split for India.
GST-Exclusive vs. GST-Inclusive — Which One Do You Need?
This is the question that causes the most errors in invoicing and bookkeeping. The two modes use different formulas and produce different results from the same starting number.
Adding GST to a price (Exclusive)
Your price does not include GST yet and you need to bill the client the GST-included total. Standard for B2B invoices.
Removing GST from a total (Inclusive)
You received a payment or see a receipt that already includes GST, and you need to separate the tax from the base. Common for retail receipts and GST remittance filing.
Common mistake: Taking 18% of ₹1,180 gives ₹212.40 — not ₹180. When a price already includes GST, you must divide by (1 + rate), not multiply by the rate. The calculator handles this automatically.
India's GST Slabs and the CGST / SGST Split
India uses a tiered GST structure with four main rate slabs. For any sale within a state, the total GST is split equally between the central and state governments.
| GST Slab | CGST | SGST | Common Examples |
|---|---|---|---|
| 0% | 0% | 0% | Fresh food, healthcare, education |
| 5% | 2.5% | 2.5% | Packaged food, economy hotels, transport |
| 12% | 6% | 6% | Processed food, mobile phones, business hotels |
| 18% | 9% | 9% | Most services, electronics, software, restaurants |
| 28% | 14% | 14% | Luxury goods, automobiles, aerated drinks |
For inter-state (IGST) transactions, the full GST goes to the central government and is later distributed. Rates above are illustrative; always verify the current slab for your specific HSN/SAC code.
GST vs. VAT — Are They the Same Thing?
The terms get used interchangeably, but there are real differences depending on which country you are in.
GST — India, Australia, Canada, New Zealand
A single, unified consumption tax that replaced a patchwork of earlier sales taxes. Simpler to administer. In India it is further subdivided (CGST/SGST/IGST) for revenue-sharing between central and state governments. Australia and New Zealand use a flat 10% and 15% respectively.
VAT — UK, EU, GCC
Collected at every point in the supply chain, with each stage reclaiming tax paid on inputs. Functionally similar to GST but with different administrative rules per country. UK VAT is 20% standard rate. On retail shelves in Europe, prices are almost always VAT-inclusive.
If you export services to overseas clients, the supply is generally zero-rated for GST purposes — meaning GST is charged at 0% and you can still claim input credits. Check your jurisdiction's rules on "export of services" before invoicing international clients.
How Input Tax Credit (ITC) Works
ITC is the mechanism that prevents GST from compounding at each stage of a supply chain — the "tax on tax" problem that plagued the older sales tax systems.
The total GST collected by the government across all stages equals the tax on the final retail price (₹360) — no more, no less. The ITC system ensures the burden is distributed across the chain rather than stacked.
GST / VAT Rates at a Glance
Rates are for general reference. Exemptions, reduced rates, and thresholds vary significantly by product category and business type. Always verify current rates with your local tax authority.
Frequently Asked Questions
Why can't I just multiply an inclusive price by the GST rate to find the tax?
Because the GST rate applies to the base price, not the total. If a ₹1,180 total includes 18% GST, the base is ₹1,000 and the tax is ₹180. Multiplying ₹1,180 × 18% gives ₹212 — an overstatement. The correct formula is: GST = Total − (Total ÷ (1 + rate)).
What is the difference between CGST, SGST, and IGST?
CGST and SGST are the two halves of intra-state GST in India — one goes to the central government, one to the state. IGST applies to inter-state transactions and is collected entirely by the central government before being shared with the destination state.
How does GST rounding work on invoices?
Most tax authorities require amounts rounded to two decimal places. The standard is 'half-up' rounding: if the third decimal is 5 or more, round up. So ₹1,125.555 becomes ₹1,125.56. The calculator applies this rule to all outputs.
Are freelancers required to charge GST?
Registration thresholds vary by country. In India, registration is mandatory once annual turnover exceeds ₹20 lakh (₹10 lakh for special category states). In Australia the threshold is A$75,000. Below these thresholds, registration is usually optional but may be beneficial for claiming ITCs.
Is this calculator suitable for official tax filings?
It is accurate for estimation and verification, but tax filings should use your official accounting software or be prepared by a registered tax professional. GST rules include exemptions, reverse-charge mechanisms, and sector-specific rates that require professional review for compliance.
Disclaimer
This tool is for estimation purposes only. GST rates, exemption thresholds, and compliance requirements change regularly and vary by jurisdiction, product category, and business type. For legally binding tax calculations and filings, consult a qualified tax professional or your country's tax authority.
Working out your margins after tax? Margin Calculator or check what a figure means in relative terms with the Percentage Calculator.