How do I calculate GST on an amount?

To add GST, multiply the taxable amount by the GST rate and divide by 100. Formula: GST = Taxable Amount × GST Rate / 100.

How do I remove GST from an inclusive amount?

To remove GST (Reverse GST), calculate the base taxable value first: Base = Inclusive Amount × 100 / (100 + GST Rate). Then subtract the base from the inclusive amount to find the tax.

What is the formula for reverse GST?

Taxable Amount = Inclusive Amount × 100 / (100 + GST Rate); GST Amount = Inclusive Amount - Taxable Amount.

How is CGST and SGST calculated?

For intra-state transactions, GST is divided equally: CGST = GST Rate / 2, and SGST = GST Rate / 2. For an 18% slab, 9% is CGST and 9% is SGST.

How is IGST calculated?

For inter-state transactions, the entire tax goes to the Center as Integrated GST (IGST). For an 18% slab, IGST is the full 18%.

Can I calculate GST after a discount?

Yes. In business transactions, GST is legally calculated on the net taxable value after subtracting trade or cash discounts from the subtotal.

Can I calculate GST for multiple quantities?

Yes. Switch on the Advanced Calculator mode to specify Unit Price and Quantity. The tool will calculate Subtotal, subtract discounts, apply tax, and show the Grand Total.

Is this GST calculator free?

Yes. This tool is completely free, secure, and operates entirely on the client-side inside your browser without uploading any data.

GST Calculator – Add/Remove GST, Reverse GST & Invoice splits

GST Calculator

Free online Indian GST Calculator. Calculate CGST, SGST, IGST, reverse GST, discounts, and invoice splits. Export results to PDF instantly.

⚡ Interactive Calculation Engine Active

Please enable JavaScript in your browser to run live computations, 2D envelope diagrams, and export PDF reports.

How to Use GST Calculator

Choose the calculation mode: Add GST (+) or Remove GST (-).
Enter the base amount (or inclusive final amount) and select the GST rate slab (5%, 12%, 18%, 28%).
Select the transaction type: Intra-state (CGST + SGST) or Inter-state (IGST).
Optionally toggle Advanced settings to add Quantity, Unit Prices, and flat/percentage discounts.
Review results, copy invoice details, or download as a PDF.

What is GST (Goods & Services Tax)?

GST is a unified destination-based indirect tax introduced in India on July 1, 2017. It replaced multiple cascading taxes like VAT, Service Tax, Central Excise, and Entry Tax. It streamlines tax administration, reduces compliance friction, and unifies the Indian market.

How to Calculate GST?

To calculate GST, you determine the net taxable value first. If a product is sold at ₹10,000 with an 18% tax rate, the GST is ₹10,000 × 18 / 100 = ₹1,800. The final invoice amount is ₹11,800. For reverse calculations, if the final price is ₹11,800, the taxable value is ₹11,800 × 100 / 118 = ₹10,000, and the GST portion is ₹1,800.

CGST vs SGST vs IGST

Transactions are categorized based on movement: - **Intra-State**: Goods/services supplied within the same state. Tax is split 50/50 between CGST (Central Government) and SGST (State Government). - **Inter-State**: Goods/services supplied between different states or imported. Collected fully as IGST by the Center and distributed to the consumption state.

GST Calculation Examples

Here are examples under standard Indian rates: - **5% (Necessities)**: ₹1,000 taxable value + 5% GST = ₹1,050 total (₹25 CGST + ₹25 SGST). - **12% (Computers/Processed foods)**: ₹5,000 + 12% = ₹5,600 total (₹300 CGST + ₹300 SGST). - **18% (Standard services)**: ₹10,000 + 18% = ₹11,800 total (₹900 CGST + ₹900 SGST). - **28% (Luxury/Sin goods)**: ₹50,000 + 28% = ₹64,000 total (₹7,000 CGST + ₹7,000 SGST).

Frequently Asked Questions

How do I calculate GST on an amount?: To add GST, multiply the taxable amount by the GST rate and divide by 100. Formula: GST = Taxable Amount × GST Rate / 100.
How do I remove GST from an inclusive amount?: To remove GST (Reverse GST), calculate the base taxable value first: Base = Inclusive Amount × 100 / (100 + GST Rate). Then subtract the base from the inclusive amount to find the tax.
What is the formula for reverse GST?: Taxable Amount = Inclusive Amount × 100 / (100 + GST Rate); GST Amount = Inclusive Amount - Taxable Amount.
How is CGST and SGST calculated?: For intra-state transactions, GST is divided equally: CGST = GST Rate / 2, and SGST = GST Rate / 2. For an 18% slab, 9% is CGST and 9% is SGST.
How is IGST calculated?: For inter-state transactions, the entire tax goes to the Center as Integrated GST (IGST). For an 18% slab, IGST is the full 18%.
Can I calculate GST after a discount?: Yes. In business transactions, GST is legally calculated on the net taxable value after subtracting trade or cash discounts from the subtotal.
Can I calculate GST for multiple quantities?: Yes. Switch on the Advanced Calculator mode to specify Unit Price and Quantity. The tool will calculate Subtotal, subtract discounts, apply tax, and show the Grand Total.
Is this GST calculator free?: Yes. This tool is completely free, secure, and operates entirely on the client-side inside your browser without uploading any data.