GST Calculator
Calculate Goods and Services Tax (GST) easily with 5%, 12%, 18%, 28% rates or custom rates with Add/Remove GST toggles.
Calculation Formula & Methodology
Goods and Services Tax (GST) is calculated differently depending on whether the base amount is inclusive or exclusive of tax. For Exclusive GST (Add GST): GST Amount = (Base Price × GST%) ÷ 100, and Total Price = Base Price + GST Amount. For Inclusive GST (Remove GST): Base Price = (Total Amount × 100) ÷ (100 + GST%), and GST Amount = Total Amount - Base Price.
Example: ₹10,000 item under 18% GST Slab
Inputs: Base Price = ₹10,000 | GST Slab = 18% (Add GST mode)
Calculation: GST Amount = (10,000 × 18) ÷ 100 = ₹1,800. Split: CGST (9%) = ₹900, SGST (9%) = ₹900.
Outcome: Total Invoice Amount = ₹11,800
Key Insights & Financial Takeaways
- Standard Indian GST Slabs: 0% (essential food items), 5% (packaged goods/transport), 12% (processed foods/computers), 18% (most capital goods, software, services), and 28% (luxury items and automobiles).
- Intra-State vs Inter-State: For sales within the same state, GST is split equally between CGST (Central GST) and SGST (State GST). For sales across states, IGST (Integrated GST) applies as a single tax.
- Reverse Calculation: When a client pays an all-inclusive bill, use the Remove GST (-) toggle to accurately report the net taxable base price on your tax returns.
How GST Calculator Works
Calculate GST online instantly. Supports Add GST (+) and Remove GST (-) for 5%, 12%, 18%, 28% tax slabs. This calculator performs all math instantly in your web browser. Input parameters are processed locally on your client machine—no financial or personal metrics are ever transmitted to external servers.
100% In-Browser Math
Calculations run locally in JavaScript. Fast, accurate, and private.
Instant Calculation
Real-time updates as you slide or type values.
Privacy Assured
Zero tracking of financial or health numbers.
Disclaimer & Regulatory Notice
This calculator is designed for informational and educational estimation purposes only. Results are theoretical estimates based on standard mathematical formulas. NS Ascertain does not provide certified financial, tax, investment, legal, or medical advice. Please consult a qualified professional before making financial commitments or medical decisions.
Frequently Asked Questions
What is the difference between GST Inclusive and GST Exclusive?
GST Exclusive means tax has not yet been added to the base price. GST Inclusive means the gross amount already incorporates the tax, so the base price must be reverse-calculated.
How do I reverse calculate base price from a GST-inclusive amount?
Divide the total inclusive amount by (1 + GST Rate / 100). For example, with 18% GST, divide the total price by 1.18 to determine the original pre-tax value.
How is GST split between Central (CGST) and State (SGST)?
For intra-state transactions (within the same state), the total GST rate is divided equally between CGST and SGST. For an 18% rate, 9% is CGST and 9% is SGST.
Which GST rate applies to software and developer consulting?
IT services, SaaS software, web development, and freelance consulting are classified under the 18% GST slab (SAC Code 9983).
Related Finance Calculators
All calculators →EMI Calculator
Calculate monthly EMI, total interest, and complete amortization schedule for home, car, or personal loans.
Income Tax Calculator (India)
Compare Old vs New Tax Regime for FY 2024-25 / FY 2025-26 with slab breakdowns, deductions, and Section 87A rebate.
SIP Calculator
Calculate expected future value, total investment, and wealth gains from Systematic Investment Plans (SIP) in mutual funds.
Compound Interest Calculator
Calculate interest growth compounded annually, semi-annually, quarterly, or monthly over time.