Which GST rate slab applies to IT services and freelancing?

In most jurisdictions implementing GST (including India), professional software development, consulting, and digital marketing services fall under the standard 18% GST slab.

What is a reverse charge mechanism (RCM)?

Under Reverse Charge, the liability to pay tax shifts from the supplier to the recipient of goods or services. This is common when businesses procure services from unregistered vendors or foreign service providers.

Finance Calculators

Goods & Services Tax (GST) Commercial Invoice Calculator

The problem: Calculating tax-inclusive base prices and splitting CGST/SGST manually for commercial billing causes ledger discrepancies.

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All GST calculations run entirely in your browser. No invoice data is transmitted.

GST Calculation Mode

Forward: add GST on top of base amount

Invoice Details

Base Amount (Ex-GST)

Enter the pre-tax invoice value

₹

GST Rate

Transaction Type

Base Amount (Ex-GST)

₹10,000.00

CGST + SGST Breakdown

CGST @ 9%₹900.00

SGST @ 9%₹900.00

Total Tax₹1,800.00

Total Invoice Amount

₹11,800.00

Effective GST rate: 18.00%

Goods & Services Tax (GST) Commercial Invoice Calculator: the complete guide

The Goods and Services Tax (GST) and Commercial Invoice Calculator computes tax liabilities, inclusive/exclusive base rates, and state-level tax bifurcations across standard GST slabs (5%, 12%, 18%, 28%). Tailored for small business owners, freelancers, and accounting teams, this tool automatically splits tax into Central GST (CGST) and State GST (SGST) for intra-state transactions or Integrated GST (IGST) for inter-state supplies.

Understanding Intra-State vs. Inter-State GST in Modern Tax Regimes

Under unified value-added tax systems such as India's GST framework, taxation depends on the geographic location of the supplier relative to the place of supply. For intra-state transactions (where both parties reside within the same state or union territory), the total GST rate is divided equally into Central GST (CGST) and State GST (SGST) — for example, an 18% slab splits into 9% CGST and 9% SGST.

For inter-state commerce (across state boundaries or international exports), the entire 18% rate is levied as Integrated GST (IGST), administered by the central government. Our calculator toggles between both models with one click.

Tax Inclusive vs. Tax Exclusive Pricing Mathematics

A common billing dilemma is reverse calculating pre-tax costs from gross retail amounts. For tax-exclusive pricing, tax is simply: Base Amount × (GST Rate / 100). However, for tax-inclusive pricing (where a consumer pays a flat $118 including 18% GST), the base price is: Total Amount / (1 + GST Rate / 100), yielding a base price of $100 and tax of $18.

Our tool provides bidirectional computation, allowing sellers to quote gross inclusive prices while ensuring their accounting invoices correctly detail pre-tax base lines.

Step by step: how to use GST Calculator

1
Select your calculation direction: Tax Exclusive (Add GST) or Tax Inclusive (Extract GST).
2
Enter your base amount or gross total invoice figure.
3
Select your applicable GST slab rate: 5%, 12%, 18%, 28%, or enter a custom rate.
4
Choose transaction type: Intra-State (CGST + SGST split) or Inter-State (IGST).
5
Copy the invoice breakdown table detailing Base Amount, CGST, SGST, IGST, and Final Total.

Security & privacy

All commercial tax calculations, ledger breakdowns, and invoice numbers remain confidential in local browser memory.