GST Calculator

Calculate GST (Goods and Services Tax) instantly - add GST to a base amount or extract GST from a total price, with CGST/SGST breakdown for Indian tax slabs (5%, 12%, 18%, 28%).

▼ Enter the base amount and select GST rate, then click Calculate
$
GST Breakdown
Original Amount
GST Rate
CGST
SGST
Total GST
Total Amount
▼ Enter the GST-inclusive total and select GST rate, then click Calculate
$
GST Breakdown
Total Amount
GST Rate
Original Amount
CGST
SGST
Total GST

What Is GST and How Is It Calculated?

GST (Goods and Services Tax) is India's unified indirect tax, charged at fixed slab rates of 5%, 12%, 18%, or 28% depending on the category of goods or service. For sales within the same state, GST splits equally into two parts — CGST (Central GST) and SGST (State GST) — each charged at half the total rate. This calculator handles both directions: adding GST to a base price, or working backward to find the original price from a GST-inclusive total.

Worked Example — Adding GST

A product priced at ₹1,000 with 18% GST splits into 9% CGST (₹90) and 9% SGST (₹90), for a total GST of ₹180 — making the final price ₹1,180.

Worked Example — Removing GST

If an invoice shows a GST-inclusive total of ₹1,180 at 18%, the original (pre-GST) price works out to ₹1,000, with ₹90 CGST and ₹90 SGST embedded in that total. This is the calculation you need when an invoice only shows the final amount and you have to back out the tax portion for accounting or reimbursement.

How to Use the GST Calculator

Choose whether you want to Add GST to a base price or Remove GST from a GST-inclusive total, select the applicable GST rate, and get an instant breakdown including CGST and SGST components.

Add GST

Enter the original amount (before tax) and select the GST rate. The calculator adds the GST on top and shows your final payable amount.

Remove GST

Enter the total amount (GST-inclusive) and select the GST rate. The calculator extracts the original base price and the GST amount from within that total.

CGST and SGST

For intra-state transactions in India, GST is typically split equally into CGST (Central GST) and SGST (State GST). For example, an 18% GST rate splits into 9% CGST + 9% SGST. This calculator shows both components automatically.

Frequently Asked Questions

It can add GST to a base amount or extract GST from a total price, with a CGST/SGST breakdown for Indian tax slabs of 5%, 12%, 18%, and 28%.

Enter the original amount (before tax) and select the GST rate, and the calculator adds the GST on top and shows your final payable amount.

Enter the total amount (GST-inclusive) and select the GST rate, and the calculator extracts the original base price and the GST amount from within that total.

For intra-state transactions in India, GST is typically split equally into CGST (Central GST) and SGST (State GST). For example, an 18% GST rate splits into 9% CGST plus 9% SGST.

Yes — for intra-state transactions, the total GST amount is automatically split equally between CGST and SGST (e.g. an 18% GST becomes 9% CGST + 9% SGST), matching how it needs to appear on a GST-compliant invoice.

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