GST calculator Online

GST Calculator Online

GST Calculator Online

Calculate GST, CGST, SGST, IGST and the final invoice amount instantly. Add GST to an amount or remove GST from an inclusive amount.

Enter the taxable amount or GST-inclusive amount.
Select States
Same State = CGST + SGST   |   Different States = IGST
This calculator provides a basic GST calculation. Actual GST treatment may depend on HSN/SAC classification, place of supply, exemptions and applicable GST provisions.

How to Calculate GST

GST calculation is simple when you know the applicable GST rate. Use the formulas below to understand how GST is added, removed and divided between CGST, SGST and IGST.

1. Add GST

Use this calculation when GST needs to be added to a taxable amount.

GST Amount
Taxable Amount × GST Rate ÷ 100
Final Amount
Taxable Amount + GST

Example:
₹10,000 + 18% GST = ₹1,800 GST
Final Amount = ₹11,800

2. Remove GST

Use this calculation when the amount already includes GST.

Taxable Value
Inclusive Amount × 100 ÷ (100 + GST Rate)
GST Amount
Inclusive Amount − Taxable Value

Example:
₹11,800 including 18% GST
Taxable Value = ₹10,000
GST = ₹1,800

3. CGST + SGST

For an intra-State supply, GST is generally divided equally between CGST and SGST.

Example: 18% GST
9% CGST + 9% SGST

On ₹10,000:
CGST = ₹900
SGST = ₹900
Total GST = ₹1,800

4. IGST

For an inter-State supply, IGST generally applies.

Example: 18% GST
18% IGST

On ₹10,000:
IGST = ₹1,800
Total Invoice = ₹11,800

GST Calculation Made Simple

The GST Calculator above performs these calculations automatically. Select Add GST when you want to calculate GST on a taxable amount, or select Remove GST when the amount already includes GST.

For the basic tax split, select the supplier state and customer state. The calculator shows CGST and SGST when the selected states are the same, and IGST when they are different.

Important: Actual GST liability may depend on the HSN/SAC classification, nature of supply, place-of-supply rules, exemptions and other applicable GST provisions. Use this calculator as a basic GST calculation tool and verify the applicable GST treatment for your transaction.

Rate update: The principal GST rate structure was rationalised from 22 September 2025. The applicable rate still depends on the exact HSN/SAC classification, exemption and conditions. Certain specified products may have separate rate or transition provisions.

GST Rates in India

GST rates depend on the classification and nature of the goods or services. The principal GST rate structure was rationalised from 22 September 2025.

0%

Nil / Exempt

Applies to specified goods and services that are nil-rated or exempt, subject to applicable conditions.

5%

Merit Rate

Applies to specified goods and services covered under the applicable GST rate notifications.

18%

Standard Rate

Applies to many goods and services under the applicable GST classification and notifications.

40%

Special Rate

Applies only to specified goods and services covered by the applicable GST provisions.

Which GST Rate Should You Use?

Do not select a GST rate only based on the product name or general category. The applicable rate should be determined using the correct HSN or SAC classification and the relevant GST notification, exemption and conditions.

The 40% rate is a special rate for specified classifications. It is not a general rate applicable to every luxury, premium or high-value product.

Quick Tip: If you are unsure about the GST rate for a product or service, first identify its HSN/SAC code and then verify the applicable GST rate.

HSN & SAC Code Search

Find the appropriate HSN or SAC classification for your goods or services before preparing your GST invoice or determining the applicable GST rate.

HSN

Harmonised System of Nomenclature

HSN codes are used for the classification of goods for GST and other trade and tax purposes.

SAC

Services Accounting Code

SAC codes are used for the classification of services supplied under GST.

Search HSN / SAC on the GST Portal

Use the official GST Portal to search HSN or SAC by code or description. GSTN provides an online search facility for HSN/SAC classification.

Search HSN / SAC on GST Portal

Important: HSN or SAC classification does not by itself determine the GST rate. The applicable rate may depend on the classification, GST notifications, exemptions, conditions and the nature of the transaction.

Before You Raise a GST Invoice

Check the HSN/SAC code, applicable GST rate, place of supply and invoice requirements before issuing the invoice. Correct classification helps avoid GST reporting and compliance problems.

GST Calculation Examples

Here are simple GST calculation examples to help you understand how the GST Calculator works for common transactions.

Example 1: Add 18% GST

Taxable amount: ₹10,000

GST @ 18% = ₹1,800
Final invoice value = ₹11,800
Example 2: Remove 18% GST

GST-inclusive amount: ₹11,800

Taxable value = ₹10,000
GST @ 18% = ₹1,800
Example 3: Karnataka to Karnataka

Taxable value: ₹1,00,000
GST rate: 18%

CGST @ 9% = ₹9,000
SGST @ 9% = ₹9,000
Total GST = ₹18,000
Final amount = ₹1,18,000
Example 4: Karnataka to Maharashtra

Taxable value: ₹1,00,000
GST rate: 18%

IGST @ 18% = ₹18,000
CGST = ₹0
SGST = ₹0
Final amount = ₹1,18,000

Quick GST Calculation Guide

Use Add GST when you have a taxable amount and want to calculate the GST and final invoice value. Use Remove GST when the amount already includes GST and you need to find the taxable value.

For a basic calculation, the same-state selection shows CGST + SGST, while different-state selection shows IGST.

Need Help With GST Compliance?

For GST registration, return filing, reconciliation and GST advisory, speak with Team IN Filings.

Contact Team IN Filings

GST Calculator – Frequently Asked Questions

Find quick answers to common questions about GST calculation, CGST, SGST, IGST and GST-inclusive amounts.

What is a GST Calculator?
A GST Calculator is an online tool that helps calculate GST on a taxable amount and determine the final invoice value. It can also calculate the taxable value when GST is already included in the amount.
How do I calculate 18% GST?
Multiply the taxable amount by 18 and divide by 100.
Example:
₹10,000 × 18% = ₹1,800 GST
Final amount = ₹11,800
How do I remove GST from an amount?
When the amount already includes GST, use:
Taxable Value = Inclusive Amount × 100 ÷ (100 + GST Rate)
For example, ₹11,800 including 18% GST gives a taxable value of ₹10,000 and GST of ₹1,800.
What is the difference between CGST, SGST and IGST?
For a basic intra-State supply, GST is generally divided into CGST and SGST. For a basic inter-State supply, IGST generally applies.

Example at 18% GST:
Same State: 9% CGST + 9% SGST
Different States: 18% IGST
Can I use this GST Calculator for an invoice?
Yes. The calculator can be used for basic GST calculations while preparing an invoice. However, the applicable GST rate, HSN/SAC classification, place of supply and other GST requirements should be verified before issuing the final invoice.
How do I find my HSN or SAC code?
HSN is generally used for goods and SAC for services. You can search the applicable HSN or SAC using the official GST Portal's Search HSN/SAC facility.

Always verify the classification and applicable GST rate before using it on your invoice or GST return.
What GST rates can I select in the calculator?
The calculator includes 0%, 5%, 18% and 40% special rate, along with an option to enter another rate when required.

The applicable GST rate should always be verified based on the relevant HSN/SAC classification and applicable GST provisions.
Is the GST Calculator suitable for all GST transactions?
The calculator is designed for common GST calculations. Certain transactions can involve specific place-of-supply rules, exemptions, reverse charge, composition scheme, special rates or other conditions. Such transactions should be reviewed separately.

Need professional GST assistance? Team IN Filings provides GST registration, GST return filing, GST reconciliation, GST advisory and other GST compliance services for businesses in Bangalore and across India.

Need Help With GST Compliance?

GST calculation is only one part of GST compliance. Correct registration, HSN/SAC classification, invoicing, input tax credit, return filing and reconciliation are equally important.

GST Registration GST Return Filing GST Reconciliation GST Advisory
Talk to Our GST Team
Team IN Filings · Bangalore
GST & Tax Compliance Support

Disclaimer: This GST Calculator is provided for general calculation purposes. GST rates, classification and tax treatment may change based on applicable law, notifications and the nature of the transaction. Professional advice should be obtained for complex or specific GST matters.

GST rate information reviewed for the current GST framework.

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