GST Calculator Online — Free GST Calculator India

What is it? Our inclusive vs exclusive gst calculator tool helps small businesses in India compute the exact Goods and Services Tax (GST) amount. Simply enter the base amount and select the GST rate (5%, 18%, or 40%) to instantly calculate 18 percent gst online and see the CGST and SGST split.

Enter the price before GST

Base Amount ₹0.00
GST Amount (18%) ₹0.00
CGST (9%) ₹0.00
SGST (9%) ₹0.00
Total Amount ₹0.00

How it works

Add GST: Base × Rate ÷ 100

Remove GST: Total ÷ (1 + Rate ÷ 100)

How to use the GST Calculator

Calculating Goods and Services Tax manually can be tedious and prone to errors. Our GST calculator for small business India is designed to provide instant, precise tax computations directly in your browser without requiring any login or data submission.

1. Adding GST to a Base Price

If you are generating an invoice and need to apply tax to a product or service, select the "Add GST" mode. Enter the base price of the item, then select the appropriate tax slab (0%, 5%, 18%, or 40%). The calculator will instantly multiply the base amount by the rate to give you the GST component, and then sum them up to provide the Total Invoice Value.

2. Removing GST (Reverse Calculation)

Often, businesses receive payments or deal with MRP products where the tax is already included in the final price. To find the original pre-tax value, you use a reverse charge mechanism GST calculator. Select the "Remove GST" mode, enter the total inclusive price, and pick the rate. The tool divides the total amount by (1 + (GST Rate / 100)) to accurately extract the base price and the tax component.

3. Understanding CGST, SGST, and IGST

India follows a dual GST model. When you want to know how to split cgst and sgst in invoice calculator results, the final GST amount is split based on the nature of the transaction:

  • Intra-State Supply (Within the same state): The total GST is divided equally into Central GST (CGST) and State GST (SGST). For example, an 18% rate becomes 9% CGST and 9% SGST.
  • Inter-State Supply (Between two different states): The entire tax amount is collected as Integrated GST (IGST) at the full rate.

Frequently Asked Questions

How to convert gst inclusive to exclusive price formula?

The convert gst inclusive to exclusive price formula is simple: divide your inclusive price by (1 + (GST Rate / 100)). Use our reverse charge mechanism gst calculator free tool above to do this instantly.

How can I calculate 18 percent gst online?

Select the 18% button in the rate selector and type your amount. The tool will calculate 18 percent gst online and show the 9% CGST and 9% SGST split for you.

Related Guides

Frequently Asked Questions

Common questions about calculating GST in India.

How do I calculate GST on a price?
To add GST to a base price, multiply the price by the GST rate and add it: Total = Base Price × (1 + Rate/100). For example, ₹1,000 at 18% GST = ₹1,000 × 1.18 = ₹1,180. To remove GST from an inclusive price, divide: Base = Inclusive Price ÷ (1 + Rate/100). So ₹1,180 ÷ 1.18 = ₹1,000.
What are the GST slabs in 2026?
Under GST 2.0 (effective 22 September 2025), the main slabs are 0%, 5%, 18%, and 40%. The old 12% and 28% slabs have been largely restructured. Essentials like food grains are at 0%, daily-use items at 5%, most goods and services at 18%, and luxury/sin goods at 40%.
What is CGST and SGST?
For intra-state transactions (within the same state), the total GST is split equally between Central GST (CGST) and State GST (SGST). So an 18% GST transaction = 9% CGST + 9% SGST. For inter-state transactions, the full 18% is charged as IGST (Integrated GST) instead.
What is IGST and when does it apply?
IGST (Integrated GST) applies when goods or services are supplied from one state to another (inter-state supply) or when imported into India. The rate is the same as the combined CGST+SGST rate but it goes entirely to the central government, which then shares the state portion with the destination state.
How do I calculate GST for a composition scheme dealer?
Composition dealers do not collect GST from customers. Instead, they pay a flat tax from their own pocket — 1% for traders, 2% for manufacturers, 5% for restaurants, and 6% for service providers — on their total turnover. They issue a Bill of Supply, not a Tax Invoice.
Can I calculate reverse GST (remove tax from MRP)?
Yes. To remove GST from an MRP-inclusive price, use: Base Price = MRP ÷ (1 + GST Rate/100). Our calculator has a "Remove GST" mode that does this automatically. Just toggle to "Remove GST", enter the inclusive price, and select the rate.
Which GST rate applies to professional services like consulting?
Most professional services — consulting, legal, accounting, IT, marketing — attract 18% GST. Some specified services like healthcare, education, and some financial services are exempt (0%). Always verify the SAC code for your specific service to confirm the correct rate.
Is GST calculated on the price before or after discount?
GST is calculated on the discounted price if the discount is mentioned on the invoice. If a pre-sale discount is agreed upon before or at the time of supply and is reflected on the invoice, GST applies on the post-discount amount. Post-sale discounts with credit notes require ITC reversal from the buyer.
Does GST apply to exports?
No. Exports are zero-rated under GST, meaning no GST is charged on the export invoice. Exporters can either claim a refund of input tax credit paid on raw materials or export under a Letter of Undertaking (LUT) without paying IGST upfront.
What is the GST rate on gold and jewellery?
Gold (including bars, coins, and jewellery) attracts 3% GST. Making charges for jewellery are taxed separately at 5%. So a ₹1,00,000 gold purchase with ₹5,000 making charges would attract ₹3,000 GST on gold + ₹250 GST on making charges.