Financial Calculators
GST Calculator
Calculate GST amount, CGST, SGST, and IGST forward and reverse on any amount.
This tool provides an estimate or a starting draft. Check the assumptions and current official requirements before relying on the result. It does not replace qualified financial, legal or medical advice.
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The GST Calculator helps businesses, freelancers, and consumers calculate the exact GST amount on any transaction. GST (Goods and Services Tax) was introduced in India on July 1, 2017, replacing a complex web of central and state taxes with a unified indirect tax structure. GST has four primary slabs: 5%, 12%, 18%, and 28%, applicable to different goods and services.
Our calculator supports both forward calculation (adding GST to a base price to get the total) and reverse calculation (removing GST from an inclusive price to recover the base amount). This is essential for professionals who receive GST-inclusive invoices and need to determine the taxable value. The tool also splits the tax into CGST and SGST for intra-state transactions, or IGST for inter-state supply.
For regular filers, the GST calculator eliminates manual errors in invoice preparation. Freelancers providing services under ₹20 lakh aggregate turnover are exempt from registration but must still track whether their clients deduct GST. The most common rates for services are 18% (IT, consulting, design) and 5% (basic food, transport). Zero-rated categories include exports and essential medicines.
How to use this utility
- Use the controls below—paste text, pick files, or adjust options as described on the tool.
- Click the main action button. Processing runs in your browser on this device.
- Download or copy the output. Check the processing note for any external services used by this operation.
Common use cases
- Freelancers and consultants preparing GST-compliant invoices for clients
- Retailers adding GST to MRP to determine consumer billing price
- Importers calculating IGST on interstate goods movement
- Customers verifying GST on restaurant bills, hotel stays, or online purchases
- Finance teams reconciling input tax credit (ITC) claims
Tips for best results
- 1For composite supply (e.g., food + packaging), apply the GST rate of the principal supply
- 2If you're under ₹20 lakh turnover threshold, you don't need to charge GST to clients
- 3Restaurants have two GST regimes: 5% without ITC for dine-in; 18% for air-conditioned restaurants was revised
- 4Services between related parties require market-value GST even if no consideration is charged
- 5Always mention GSTIN, HSN/SAC code, and GST rate on B2B invoices for ITC eligibility
Frequently asked questions
- Is Konnect2Tools free?
- Yes. These in-browser tools are completely free to use with no account required for core functionality.
- Do my files leave my device?
- Browser document operations run locally, except where the operation uses an external service, such as AI summarisation. Read the processing note before using sensitive inputs.
- Is the GST Calculator tool safe to use?
- Local operations process document content on your device. External-service operations may send inputs as described in the processing note. Keep originals and inspect the output.
- What is the difference between CGST, SGST, and IGST?
- CGST (Central GST) and SGST (State GST) are each levied at half the applicable GST rate for intra-state transactions — e.g., 18% GST = 9% CGST + 9% SGST. IGST (Integrated GST) is the full rate applied on inter-state supply and is later apportioned between Centre and State.
- How do I remove GST from an inclusive amount?
- Use the reverse formula: Base price = Total price ÷ (1 + GST rate/100). For a ₹11,800 total at 18% GST: Base = 11,800 ÷ 1.18 = ₹10,000. GST = ₹1,800.
- Is GST applicable on all services?
- Most services attract 18% GST. Exceptions include healthcare (exempt), educational services (exempt), and certain financial services (mixed). Always check the official CBIC notification for your specific SAC code.
- What is the threshold for GST registration?
- Businesses with annual aggregate turnover exceeding ₹20 lakh (₹10 lakh for special category states) must register for GST. E-commerce sellers must register regardless of turnover.
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