If you've ever stared at a GST invoice wondering why your ₹10,000 purchase suddenly became ₹11,800 — or tried to reverse-calculate how much tax is hidden inside a price — you're not alone. GST (Goods and Services Tax) was introduced in India in July 2017 to replace a maze of central and state taxes, but understanding how it breaks down into CGST, SGST, and IGST can still feel overwhelming. Whether you're a small business owner filing monthly returns, a freelancer raising invoices, or simply a curious consumer, knowing the exact GST breakdown on every rupee matters.
Our GST Breakdown Calculator does the heavy lifting instantly — you enter the base amount and GST rate, and it tells you exactly how much is CGST, how much is SGST (or IGST for interstate transactions), and what the final invoice total should be. This guide goes a step further: it explains the logic behind the math, walks you through India's 2026 GST rate slabs with real product examples, and helps you avoid the costly mistakes that trip up thousands of businesses every year during GST audits and return filing.
Calculate Your GST Breakdown Instantly
Enter any amount and GST rate to get the exact CGST, SGST, and IGST split for your invoice. Free, accurate, and takes under 10 seconds.
What is GST Breakdown and Why Does It Matter for Invoicing?
GST breakdown refers to splitting a single GST charge into its component taxes — CGST (Central GST), SGST (State GST), and IGST (Integrated GST). Every GST-registered business in India must show this breakdown explicitly on every invoice. Getting it wrong isn't just a paperwork issue — it can result in demand notices, penalties, and lost Input Tax Credit (ITC).
The Three Components of GST
- CGST: Goes to the Central Government. Always half the total GST rate.
- SGST: Goes to the State Government where the buyer is located. Always half the total GST rate. Applicable only for intra-state transactions.
- IGST: Applicable for inter-state transactions and imports. Equal to the full GST rate (CGST + SGST combined). Goes to the Centre, which then settles with the destination state.
Why the Breakdown Matters on Your Invoice
Under GST law (CGST Act, 2017), a tax invoice must separately disclose CGST, SGST/UTGST, or IGST amounts. If you just write "GST: ₹1,800" without splitting it, your invoice is technically non-compliant. Your buyer cannot claim ITC on a non-compliant invoice. In a business-to-business (B2B) sale, that can cost your customer thousands in lost refunds — and they'll blame you.
Intra-State Example (Same State)
You sell a laptop worth ₹50,000 (exclusive of GST) to a buyer in Maharashtra, and you are also in Maharashtra. GST rate: 18%.
- CGST @ 9% = ₹4,500
- SGST @ 9% = ₹4,500
- Total Invoice Value = ₹59,000
Inter-State Example (Different States)
Same laptop, same seller in Maharashtra, but buyer is in Karnataka.
- IGST @ 18% = ₹9,000
- Total Invoice Value = ₹59,000
The total amount is the same — only the breakdown changes. But on GSTR-1, these go into completely different tables, which is why the distinction matters for your returns.
India's GST Rate Slabs in 2026: Complete Reference Table
India's GST council has maintained the core four-rate structure since 2017, though individual product classifications get revised periodically. Here is the complete, up-to-date slab reference for 2026 with real product and service examples:
GST Rate Slab Table (2026)
| GST Rate | CGST | SGST | Category | Examples |
|---|---|---|---|---|
| 0% | 0% | 0% | Exempt / Nil-rated | Fresh vegetables, milk, eggs, bread, salt, cereals, educational services, healthcare |
| 5% | 2.5% | 2.5% | Essential goods | Packaged food, edible oils, sugar, tea, coffee, domestic LPG, economy hotel rooms (<₹1,000/night), transport services |
| 12% | 6% | 6% | Standard goods | Mobile phones, computers, processed food, butter, cheese, agarbatti, medicines (non-exempt), business class air travel |
| 18% | 9% | 9% | Standard rate (most common) | Restaurants (AC), financial services, IT services, telecom, hair oil, toothpaste, soap, capital goods, mid-range hotels |
| 28% | 14% | 14% | Luxury / demerit goods | Cars, motorcycles (above 350cc), air conditioners, cigarettes, pan masala, luxury hotels (>₹7,500/night), aerated drinks |
Common Service Tax Rates at a Glance
| Service Type | GST Rate | Example Monthly Bill | GST Amount |
|---|---|---|---|
| Freelance IT/Software | 18% | ₹50,000 | ₹9,000 |
| Restaurant (AC) | 5% | ₹2,000 | ₹100 |
| Insurance Premium | 18% | ₹10,000 | ₹1,800 |
| Chartered Accountant | 18% | ₹15,000 | ₹2,700 |
| Event Management | 18% | ₹1,00,000 | ₹18,000 |
| Goods Transport (GTA) | 5% | ₹5,000 | ₹250 |
How to Find the Right GST Rate for Your Product
Every product has an HSN (Harmonized System of Nomenclature) code and every service has an SAC (Service Accounting Code). The GST rate is linked to the HSN/SAC. You can look up your code on the CBIC website (cbic.gov.in) or use the GST Portal's rate finder. Businesses with turnover above ₹5 crore must mention the 6-digit HSN code on every invoice.
Inclusive vs Exclusive GST: Which Does Your Bill Use?
This is where most people get confused — and where billing software sometimes gets it wrong too. When a price is shown, is GST already included in it, or is it added on top? The difference in your final payment can be significant.
GST Exclusive (Tax Added on Top)
The displayed price does not include GST. The tax is calculated on the base price and added separately. This is the standard format for B2B invoices.
Formula (GST Exclusive):
GST Amount = Base Price × GST Rate ÷ 100
Final Price = Base Price + GST Amount
Example: A web designer charges ₹20,000 for a website (exclusive of GST). GST rate: 18%.
- GST = ₹20,000 × 18% = ₹3,600
- CGST = ₹1,800 | SGST = ₹1,800
- Invoice Total = ₹23,600
GST Inclusive (Tax Already Inside the Price)
The displayed price already contains GST. You need to extract the base price and tax from it. Common in retail (MRP on consumer products always includes GST).
Formula (GST Inclusive — Reverse Calculation):
GST Amount = Total Price × GST Rate ÷ (100 + GST Rate)
Base Price = Total Price − GST Amount
Example: A mobile phone has MRP ₹18,000 inclusive of 12% GST.
- GST = ₹18,000 × 12 ÷ 112 = ₹1,928.57
- Base Price = ₹18,000 − ₹1,928.57 = ₹16,071.43
- CGST = ₹964.29 | SGST = ₹964.29
Side-by-Side Comparison Table
| Aspect | GST Exclusive | GST Inclusive |
|---|---|---|
| Where used | B2B invoices, service agreements | Retail/consumer sales, MRP products |
| Price shown | Base amount only | Final amount (tax inside) |
| Calculation | Add GST on top | Reverse-extract GST from total |
| Invoice format | Shows base + tax separately | Shows total; tax disclosed separately |
| Example: ₹10,000 at 18% | Pay ₹11,800 | Pay ₹10,000 (tax = ₹1,525.42) |
How to Calculate GST Manually: Formula + Worked Examples
Even though our calculator handles this instantly, understanding the manual calculation helps you catch errors, train your team, and explain invoices to clients. Here are the three core formulas you need:
Formula 1: Calculating GST on a Base Amount
GST Amount = Base Amount × (GST Rate / 100)
CGST = GST Amount / 2
SGST = GST Amount / 2
Total Invoice = Base Amount + GST Amount
Worked Example — IT Services Invoice:
A Bengaluru-based software firm bills a client in Bengaluru ₹75,000 for software development. GST rate: 18%.
- GST = ₹75,000 × 18/100 = ₹13,500
- CGST = ₹6,750 | SGST = ₹6,750
- Final Invoice = ₹88,500
Formula 2: Reverse GST (Extract from Inclusive Price)
Base Amount = Total Price × 100 / (100 + GST Rate)
GST Amount = Total Price − Base Amount
Worked Example — Restaurant Bill:
Your restaurant bill comes to ₹2,500 inclusive of 5% GST. How much tax did you pay?
- Base = ₹2,500 × 100/105 = ₹2,380.95
- GST = ₹2,500 − ₹2,380.95 = ₹119.05
- CGST = ₹59.52 | SGST = ₹59.52
Formula 3: IGST for Interstate Transactions
IGST = Base Amount × (Full GST Rate / 100)
Total Invoice = Base Amount + IGST
Worked Example — Interstate Goods Sale:
A Delhi distributor sells goods worth ₹1,20,000 to a buyer in Rajasthan. GST rate: 12%.
- IGST = ₹1,20,000 × 12/100 = ₹14,400
- Total Invoice = ₹1,34,400
- (No CGST or SGST — only IGST applies)
Quick Reference: GST Amount on Common Invoice Values
| Base Amount (₹) | GST @ 5% | GST @ 12% | GST @ 18% | GST @ 28% |
|---|---|---|---|---|
| 5,000 | 250 | 600 | 900 | 1,400 |
| 10,000 | 500 | 1,200 | 1,800 | 2,800 |
| 25,000 | 1,250 | 3,000 | 4,500 | 7,000 |
| 50,000 | 2,500 | 6,000 | 9,000 | 14,000 |
| 1,00,000 | 5,000 | 12,000 | 18,000 | 28,000 |
| 5,00,000 | 25,000 | 60,000 | 90,000 | 1,40,000 |
GST on Services vs Goods: Key Differences
While the GST calculation formula is the same, there are several important practical differences in how GST applies to goods versus services. Getting this wrong is one of the top reasons for GST notices.
Place of Supply Rules
For goods: the place of supply is where the goods are delivered. If you deliver from Mumbai to Pune (same state), CGST + SGST apply. If you ship from Mumbai to Delhi (different state), IGST applies.
For services: the place of supply rules are more complex. Generally, it's the location of the service recipient. But for certain services (like hotel accommodation, event services), it's where the service is physically performed — regardless of where the billing party is registered.
Time of Supply
| Aspect | Goods | Services |
|---|---|---|
| Time of Supply | Earlier of: invoice date or delivery date | Earlier of: invoice date or date of payment |
| Invoice Deadline | Before or at delivery | Within 30 days of service completion |
| Reverse Charge | Specific goods only (e.g., cashew, silk) | More common (legal, CAs, etc. from unregistered) |
Reverse Charge Mechanism (RCM) on Services
Under RCM, the buyer pays GST instead of the seller. This applies when you receive services from certain categories — for example, if a GST-registered company takes services from a freelance lawyer or unregistered supplier. In this case, you pay the GST directly to the government and can then claim it back as ITC. Our GST breakdown calculator works for both regular and RCM scenarios.
Input Tax Credit (ITC): How GST Breakdown Affects Your Refund
Input Tax Credit is the most powerful feature of GST for businesses — it prevents the cascading effect of tax-on-tax. But your ability to claim ITC depends entirely on getting your GST breakdown right on both your purchase invoices and your sales invoices.
How ITC Works — A Simple Example
You manufacture furniture and sell it at 18% GST. You buy raw wood at 12% GST. Here's how ITC flows:
- You buy wood worth ₹1,00,000 + ₹12,000 GST (12%). You pay ₹1,12,000 total.
- You sell furniture for ₹2,50,000 + ₹45,000 GST (18%). Customer pays ₹2,95,000.
- GST you owe to government = ₹45,000 − ₹12,000 (ITC) = ₹33,000
Without ITC, you'd pay ₹45,000. With ITC, you only pay ₹33,000. That ₹12,000 saving flows through only if your purchase invoices correctly show the GST breakdown.
- CGST credit can offset CGST or IGST liability (not SGST)
- SGST credit can offset SGST or IGST liability (not CGST)
- IGST credit can offset IGST, then CGST, then SGST
ITC Eligibility Conditions
| Condition | Requirement |
|---|---|
| Invoice compliance | Supplier must have issued a GST-compliant tax invoice with correct breakdown |
| Supplier filing | Supplier must have filed their GSTR-1 and the invoice must appear in your GSTR-2B |
| Payment | You must pay the supplier within 180 days of invoice date |
| Business purpose | Goods/services must be used for taxable business activities (not personal use) |
| Blocked credits | Motor vehicles (passenger), food & beverages, club memberships — ITC blocked under Section 17(5) |
Common GST Calculation Mistakes That Cost Businesses Money
After working through thousands of GST queries, these are the mistakes that come up again and again — and each one can trigger a GST audit, demand notice, or penalty.
Mistake 1: Applying Wrong GST Rate
Misclassifying a product's HSN code is the #1 error. Example: charging 12% on a product that should be 18% means you've undercharged — and the government will demand the difference plus interest at 18% per annum. The reverse (overcharging) means your customer paid more than necessary and will raise a dispute.
Mistake 2: Mixing IGST and CGST+SGST
Charging CGST+SGST on an interstate supply (which should be IGST) is a serious error. The wrong tax goes to the wrong government, and correcting it requires an amendment invoice plus potentially a refund claim — both of which take time and generate scrutiny.
Mistake 3: Wrong Place of Supply Determination
Especially common for service businesses. If you're in Hyderabad and serving a client in Chennai, IGST applies. Charging CGST+SGST here is incorrect and will mismatch in the GSTN system when the client tries to claim ITC.
Mistake 4: Not Accounting for RCM
If you receive legal services from a lawyer, you must self-invoice and pay GST under RCM — even if the lawyer didn't charge you GST. Many businesses miss this entirely and face demand notices years later with accumulated interest.
Mistake 5: Rounding Errors on GST
GST should be rounded off to the nearest rupee at the invoice level (not the line-item level, then aggregated). Many businesses round each line item separately, leading to discrepancies that cause mismatches in GSTR filings. Always calculate GST at the invoice total and round once.
Mistake 6: Ignoring the Composition Scheme
Small businesses with turnover under ₹1.5 crore (goods) or ₹50 lakh (services) can opt for the Composition Scheme and pay a flat low rate (1%–6%) without complex ITC tracking. If eligible but not enrolled, you're paying more GST than you need to.
How to Use the Tool (Step by Step)
- 1
Enter your base amount
Type the pre-GST price of your product or service. For example, if you're billing ₹50,000 for consulting services, enter 50000. Do not include any existing taxes in this field.
- 2
Select the GST rate
Choose the applicable GST rate from the dropdown: 0%, 5%, 12%, 18%, or 28%. If unsure, look up your product's HSN code on the CBIC portal. Most services in India fall under 18%.
- 3
Choose transaction type
Select whether this is an intra-state transaction (same state — CGST + SGST applies) or inter-state (different states — IGST applies). This determines how the breakdown is displayed.
- 4
Toggle inclusive or exclusive
If your price already includes GST (like an MRP), toggle to 'GST Inclusive' mode. The calculator will then reverse-calculate the base price and tax. For B2B invoices, keep it on 'Exclusive'.
- 5
Copy the breakdown to your invoice
The calculator shows you CGST amount, SGST/IGST amount, total GST, and the final invoice value. Use these exact figures on your tax invoice to ensure GST compliance and allow your buyer to claim ITC.
Frequently Asked Questions
What is the difference between CGST, SGST, and IGST?+−
CGST (Central GST) goes to the Central Government and SGST (State GST) goes to the State Government — both apply on intra-state transactions, each at half the total GST rate. IGST (Integrated GST) applies on inter-state transactions at the full GST rate and is collected by the Centre, which then distributes the state's share to the destination state.
How do I calculate 18% GST on ₹10,000?+−
For GST-exclusive pricing: GST = ₹10,000 × 18% = ₹1,800. If intra-state: CGST = ₹900, SGST = ₹900. Final invoice = ₹11,800. If inter-state: IGST = ₹1,800. Final invoice = ₹11,800.
What does GST inclusive mean on an invoice?+−
GST inclusive means the price shown already contains the GST. To find the tax component, use: GST = Total Price × GST Rate ÷ (100 + GST Rate). For example, ₹11,800 inclusive of 18% GST contains GST of ₹11,800 × 18/118 = ₹1,800.
Can I claim ITC on all my GST purchases?+−
Not on all purchases. ITC is blocked under Section 17(5) for: passenger vehicles, food and beverages, outdoor catering, health club memberships, beauty treatments, life insurance, and goods used for personal consumption. For everything else used in your business, ITC is generally available if the invoice is compliant.
What GST rate applies to freelance services?+−
Most freelance professional services (IT, design, writing, consulting, legal, accounting) attract 18% GST. If your annual turnover exceeds ₹20 lakh (₹10 lakh in special category states), you must register for GST and charge 18% on your invoices.
How many digits of HSN code do I need on my invoice?+−
It depends on your annual turnover: up to ₹5 crore — 4-digit HSN code required; above ₹5 crore — 6-digit HSN code required. For B2C (consumer) invoices, HSN codes are required only if turnover exceeds ₹5 crore.
What is the GST rate on restaurant food?+−
Restaurants (not in hotels with room tariff above ₹7,500) charge 5% GST with no ITC. AC restaurants and non-AC restaurants both charge 5% as of current GST rules. Hotels with room tariff above ₹7,500 charge 18% GST in their restaurant.
Is GST applicable on exports?+−
Exports are zero-rated under GST — meaning the rate is 0% but you can still claim ITC on inputs used for export. You can either export under a Letter of Undertaking (LUT) without paying IGST, or pay IGST and claim a refund later. The LUT route is simpler for regular exporters.
Calculate Your GST Breakdown Instantly
Enter any amount and GST rate to get the exact CGST, SGST, and IGST split for your invoice. Free, accurate, and takes under 10 seconds.
Open GST Breakdown CalculatorRelated Guides
How to Calculate GST in India — Formula, Examples & Calculator (2026)
Complete guide to calculating GST for any good or service in India — inclusive, exclusive, IGST, CGST, SGST.
TDS Calculator
Calculate TDS on salary, FD interest, rent, freelancing income, and property sale — know exactly how much is deducted and when.
Salary Calculator India
Understand your CTC breakup, compare old vs new tax regimes, and calculate exact take-home salary.