Calculate GST
What is GST?
Goods and Services Tax (GST) is India's comprehensive indirect tax that replaced multiple cascading taxes (VAT, Service Tax, Excise Duty, etc.) on 1 July 2017. It's levied on the supply of goods and services at each stage of the supply chain, with credit available for tax paid at previous stages.
GST Structure in India
- CGST (Central GST): Collected by the Central Government on intra-state supplies. Rate = half of total GST rate.
- SGST (State GST): Collected by the State Government on intra-state supplies. Rate = half of total GST rate.
- IGST (Integrated GST): Collected by the Central Government on inter-state supplies. Rate = full GST rate.
- UTGST: Replaces SGST for Union Territories without legislature.
How to Add GST
Final Price = Original Price + GST Amount
How to Remove GST (Reverse Calculation)
GST Amount = GST-Inclusive Price − Original Price
GST Slabs in India (2025-26)
| GST Slab | Category | Examples |
|---|---|---|
| 0% (Exempt) | Essentials | Fresh fruits, vegetables, milk, eggs, bread, salt, natural honey |
| 5% | Basic necessities | Sugar, tea, edible oil, coal, economy class flights, fertilizers, shoes under ₹500 |
| 12% | Standard goods | Butter, ghee, mobile phones, business class flights, frozen food, fruit juices |
| 18% | Most goods & services | Hair oil, toothpaste, IT services, financial services, restaurants (AC), steel, capital goods |
| 28% | Luxury & sin goods | Cars, motorcycles, ACs, refrigerators, cement, aerated drinks, pan masala, tobacco |
Note: Some items at 28% also attract a GST Compensation Cess (e.g., luxury cars, aerated drinks, tobacco products). The cess ranges from 1% to 290% depending on the product.
GST Calculation Examples
Example 1: Adding GST to a Product
A laptop costs ₹50,000 (before GST) and falls under the 18% slab. Sold within the same state:
- CGST (9%) = ₹4,500
- SGST (9%) = ₹4,500
- Total GST = ₹9,000
- Final Price = ₹59,000
Example 2: Removing GST from a Bill
Your restaurant bill is ₹2,360 (GST inclusive) at 18% GST:
- Original Price = 2,360 × 100 / 118 = ₹2,000
- GST = ₹360 (CGST ₹180 + SGST ₹180)
Example 3: Inter-State Supply
A Delhi seller sells goods worth ₹1,00,000 to a buyer in Mumbai at 12% GST:
- IGST (12%) = ₹12,000
- Total = ₹1,12,000
Since it's inter-state, only IGST is charged (no CGST/SGST split).
GST for Business Owners
Who Needs to Register?
- Businesses with annual turnover above ₹40 lakh (₹20 lakh for services, ₹10 lakh for special category states)
- E-commerce operators and sellers on e-commerce platforms
- Inter-state suppliers (regardless of turnover)
- Casual taxable persons and non-resident taxable persons
Input Tax Credit (ITC)
ITC is the backbone of GST. If you pay ₹18,000 GST on raw materials and charge ₹27,000 GST on finished goods, you only pay ₹9,000 to the government. This eliminates the cascading "tax on tax" problem of the old system.
Composition Scheme
Small businesses with turnover up to ₹1.5 crore can opt for the Composition Scheme with a flat rate of 1-5% on turnover. Simpler compliance, but no ITC and no inter-state supply allowed.
GST Filing Calendar
| Return | Who Must File | Due Date | Frequency |
|---|---|---|---|
| GSTR-1 | All regular taxpayers | 11th of next month | Monthly |
| GSTR-3B | All regular taxpayers | 20th of next month | Monthly |
| GSTR-4 | Composition scheme | 30th April | Annual |
| GSTR-9 | All regular (>₹2Cr turnover) | 31st December | Annual |
GST Before vs After: What Changed for You?
Before GST (pre-July 2017), India had a complex web of indirect taxes. Here's how the switch affected everyday prices and businesses:
| Item | Old Tax Rate | GST Rate | Impact |
|---|---|---|---|
| Restaurant meal | VAT 14.5% + Service Tax 6% | 5% (non-AC) / 18% (AC) | Cheaper (non-AC) |
| Movie ticket (≤₹100) | Entertainment Tax 28-110% | 12% | Much cheaper |
| Car | Excise 12.5% + VAT 14.5% + Cess | 28% + Cess | Similar |
| Mobile phone | VAT 5-14% (varied by state) | 12% | Standardized |
| Cab ride | Service Tax 6% | 5% | Cheaper |
| Insurance premium | Service Tax 15% | 18% | More expensive |
| IT/Software services | Service Tax 15% | 18% | More expensive |
The biggest win wasn't rate changes — it was eliminating the cascading "tax on tax" effect. Under the old system, manufacturers paid excise, wholesalers paid VAT on the excise-inclusive price, and retailers paid VAT again. Each layer added tax on top of tax. GST's Input Tax Credit system ensures tax is paid only on the value added at each stage.
Common GST Mistakes to Avoid
- 1. Wrong HSN/SAC code: Using an incorrect Harmonized System of Nomenclature code means you may charge the wrong GST slab. A toothbrush is 18% but a toothpowder is 12%. Verify codes on the CBIC website before invoicing.
- 2. Not claiming eligible ITC: Many businesses forget to claim ITC on rent, professional services, office supplies, and even courier charges. Every rupee of unclaimed ITC is money left on the table.
- 3. Ignoring the ₹2 lakh e-invoice threshold: From August 2023, e-invoicing is mandatory for businesses with turnover above ₹5 crore. Non-compliance means the recipient can't claim ITC on your invoices.
- 4. Misclassifying supply type: Charging CGST+SGST on an inter-state supply (or vice versa) creates ITC reconciliation nightmares. Verify billing and shipping addresses carefully.
- 5. Late filing penalties stack up: ₹50/day doesn't sound like much, but it's ₹1,500/month per return. With GSTR-1 + GSTR-3B, that's ₹3,000/month. Over a year of missed filings, penalties can exceed ₹36,000 plus 18% interest on unpaid tax.
- 6. Not issuing credit notes properly: Returns, discounts, and order cancellations need proper GST credit notes within the prescribed time. Without them, you overpay GST and your customer overpays too.
- 7. Mixing exempt and taxable supplies: If you sell both GST-exempt and taxable goods, you must reverse proportional ITC on exempt supplies. Many businesses miss this, leading to notices during audits.
- 8. Ignoring Reverse Charge Mechanism (RCM): Certain supplies (like services from advocates, goods transport agencies, or unregistered dealers above ₹5,000/day) require the buyer to pay GST under RCM. Missing this triggers demand notices with interest.
GST Impact on Different Industries
E-commerce
E-commerce operators must collect TCS (Tax Collected at Source) at 1% of net taxable supplies. Sellers on platforms like Amazon, Flipkart, and Meesho must register for GST regardless of turnover — the ₹40L threshold doesn't apply to e-commerce sellers.
Real Estate
Under-construction properties attract 5% GST (1% for affordable housing under ₹45L). Ready-to-move-in properties with completion certificate are exempt. Developers cannot claim ITC under the new 5% rate, which was a tradeoff for the lower rate.
Freelancers & Consultants
Services attract 18% GST. Freelancers earning above ₹20L must register. Export of services is zero-rated — you charge 0% GST but can still claim ITC on inputs, making it beneficial for IT exporters. Use a Letter of Undertaking (LUT) to export without paying IGST.
Restaurants & Hotels
Non-AC restaurants: 5% (no ITC). AC restaurants: 5% (no ITC). Hotels with room tariff above ₹7,500: 18% (with ITC). Cloud kitchens and food delivery: classified as restaurant service at 5% when the food aggregator delivers, with the aggregator paying GST.
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