GST Calculator – Add or Remove GST from Any Amount Instantly
This free GST calculator helps you instantly add GST to a base price or remove GST from a GST-inclusive amount. Supports all four official Indian GST slabs — 5%, 12%, 18% and 28% — plus custom rates. No signup, works instantly on all devices.
What is GST?
Goods and Services Tax (GST) is a comprehensive indirect tax levied on the manufacture, sale and consumption of goods and services across India. It was introduced on 1 July 2017 and replaced a complex web of indirect taxes including VAT, service tax, central excise duty and octroi. GST is a destination-based tax — it is collected at the point of consumption, not production.
GST Rate Slabs in India (2025)
| GST Rate | Category | Examples |
|---|
| 0% | Exempt / Essential | Fresh vegetables, milk, eggs, books, education, healthcare |
| 5% | Basic Necessities | Packaged food, footwear under ₹1000, transport services, fertilizers |
| 12% | Standard Goods | Processed food, computers, mobile phones, business class travel |
| 18% | Most Services & Goods | Restaurants, banking, telecom, insurance, electronics, software |
| 28% | Luxury & Sin Goods | Cars, motorcycles, AC, tobacco, aerated drinks, cement |
GST Calculation Formula
Adding GST (Exclusive → Inclusive)
GST Amount = Original Price × (GST Rate ÷ 100)
Final Price = Original Price + GST Amount
Removing GST (Inclusive → Exclusive)
Original Price = GST-Inclusive Price ÷ (1 + GST Rate ÷ 100)
GST Amount = GST-Inclusive Price − Original Price
GST Calculation Examples
| Scenario | Amount | GST Rate | GST Amount | Final Price |
|---|
| Restaurant bill (add GST) | ₹1,000 | 5% | ₹50 | ₹1,050 |
| Mobile phone (add GST) | ₹15,000 | 12% | ₹1,800 | ₹16,800 |
| Software service (add GST) | ₹50,000 | 18% | ₹9,000 | ₹59,000 |
| Car (remove GST from ₹15L) | ₹15,00,000 | 28% | ₹3,28,125 | ₹11,71,875 |
💡 GST is charged on the transaction value — the actual price paid. Discounts given before the sale reduce taxable value. Post-sale discounts may or may not reduce GST liability depending on whether they are pre-agreed.
Frequently Asked Questions
What is CGST, SGST and IGST?When a transaction happens within one state, GST is split equally between CGST (Central) and SGST (State). When a transaction crosses state borders, IGST (Integrated GST) is charged, which equals CGST + SGST combined.
Who needs to register for GST?Businesses with annual turnover above ₹40 lakh (₹20 lakh for service providers, ₹10 lakh in special category states) must register for GST. E-commerce sellers must register regardless of turnover.
What is Input Tax Credit (ITC)?ITC allows registered businesses to deduct GST paid on purchases (inputs) from GST collected on sales. This prevents tax cascading and ensures tax is effectively paid only on the final value added.
What is the GST rate for freelancers and consultants?Most professional services, including IT, consulting, marketing and legal services, attract 18% GST. Freelancers with turnover above ₹20 lakh must register and collect GST.
Can I use a custom GST rate in this calculator?Yes — enter any rate (e.g. 0.25%, 3%, 7.5%) in the custom rate field. The calculator updates instantly to show all GST breakdowns.