Finance & Banking CalcyZone Calculator

GST Calculator (Inclusive & Exclusive)

Add or remove GST from a price and split the tax into CGST + SGST (intra-state) or IGST (inter-state).

Taxable value (pre-GST)

₹1,000.00

Total GST

₹180.00

CGST

₹90.00

SGST / UTGST

₹90.00

Total price (incl. GST)

₹1,180.00

Step-by-step working

GST = 1,000 × 18 / 100 = ₹180
CGST = SGST = ₹180 / 2 = ₹90
Total = ₹1,000 + ₹180 = ₹1,180

Mathematical Formula

Exclusive: GST = Amount × rate / 100; Total = Amount + GST. Inclusive: Taxable value = Amount × 100 / (100 + rate); GST = Amount − Taxable value. Intra-state: CGST = SGST = GST / 2. Inter-state: IGST = GST.

Overview & Explanation

GST is levied on the taxable value of a supply. For supplies within a state it is split equally between the Centre (CGST) and the State (SGST/UTGST); for inter-state supplies the Centre levies IGST.

How It Works

Pick whether the amount already contains GST.
Back out or add tax at the chosen rate.
Split by place of supply.

Practical Applications

Preparing invoices.
Finding the pre-tax price on a bill.
Checking input tax credit.

Example 1: Add 18% GST to ₹1,000 (same state)

CGST 9% + SGST 9%.

Inputs

Amount (₹): 1000 · GST rate: 18% · Amount is: Exclusive of GST (add GST) · Type of supply: Within the same state (CGST + SGST)

= entered

Step 1

GST = 1,000 × 18 / 100 = ₹180

Step 2

CGST = SGST = ₹180 / 2 = ₹90

Step 3

Total = ₹1,000 + ₹180 = ₹1,180

Total price (incl. GST)

Result

= ₹1,180.00

Example 2: Remove 12% GST from ₹1,120 (inter-state)

Reverse GST with IGST.

Inputs

Amount (₹): 1120 · GST rate: 12% (legacy) · Amount is: Inclusive of GST (remove GST) · Type of supply: Between states (IGST)

= entered

Step 1

Taxable value = 1,120 × 100 / (100 + 12) = ₹1,000

Step 2

IGST = full GST = ₹120

Step 3

Total = ₹1,000 + ₹120 = ₹1,120

Total price (incl. GST)

Result

= ₹1,120.00

How it's calculated & sources

CBIC GST – Rates and IGST/CGST Acts

Frequently Asked Questions

How do I remove GST from an inclusive price?

Divide by (1 + rate/100). For 18%: ₹1,180 ÷ 1.18 = ₹1,000 taxable value, ₹180 GST.

When is IGST charged instead of CGST + SGST?

When the supplier’s location and the place of supply are in different states or union territories, and on imports.

What are the GST rates?

Common slabs are 0%, 5% and 18%, with 3% for gold, 40% for certain sin/luxury goods and legacy 12%/28% rates where still notified. Check the CBIC rate notification for your item.

Is CGST always half of GST?

Yes. For intra-state supplies CGST and SGST are each half of the total rate.