A GST Calculator is a free online tool that allows individuals, business owners, traders, accountants, and students to instantly calculate the Goods and Services Tax (GST) applicable on any product or service. Instead of doing manual calculations that can lead to errors, our GST Calculator gives you accurate results within seconds — including a complete breakdown of CGST, SGST, and IGST.

GST was introduced in India on 1st July 2017, replacing multiple indirect taxes like VAT, Service Tax, and Central Excise Duty. Today, GST applies to almost every good and service traded in India, making a reliable GST calculator an essential tool for businesses of all sizes.

How to Use This GST Calculator?

Step 1: Select the mode — "Add GST" to calculate tax on a base amount, or "Remove GST" to find the base price from a GST-inclusive total.
Step 2: Enter the amount in the input field.
Step 3: Select the applicable GST rate — 0%, 5%, 12%, 18%, or 28%. You can also enter a custom rate.
Step 4: Click "Calculate GST" to see the instant breakdown of Base Amount, Total GST, CGST, SGST, and Invoice Total.

GST Calculation Formulas

1. Add GST (Calculate GST on Base Amount)

📌 GST Amount = (Base Amount × GST Rate) ÷ 100

📌 Total Invoice Amount = Base Amount + GST Amount

📌 CGST = GST Amount ÷ 2 | SGST = GST Amount ÷ 2

Example: Base price = ₹10,000, GST Rate = 18% → GST = ₹1,800 (CGST ₹900 + SGST ₹900) → Total = ₹11,800

2. Remove GST / Reverse GST Calculation

📌 Base Amount = Total Amount ÷ (1 + GST Rate ÷ 100)

📌 GST Amount = Total Amount − Base Amount

Example: Total = ₹11,800, Rate = 18% → Base = ₹10,000, GST = ₹1,800

3. CGST vs SGST vs IGST

CGST: Collected by Central Government on intra-state transactions (= half the GST rate)
SGST: Collected by State Government on intra-state transactions (= half the GST rate)
IGST: Levied on inter-state transactions — goes entirely to the Central Government
UTGST: Applicable in Union Territories instead of SGST

GST Slab Rates in India 2025

GST Rate	Category	Examples	CGST+SGST
0%	Exempt	Milk, Fruits, Vegetables, Bread, Education, Healthcare	0%+0%
5%	Basic Necessities	Tea, Coffee, Edible Oil, Sugar, Coal, Books, Railways	2.5%+2.5%
12%	Standard Goods	Mobile Phones, Butter, Cheese, Processed Food, Clothing	6%+6%
18%	Services & Mid-Range	Restaurants, IT Services, Soap, Toothpaste, Hair Oil, Cement	9%+9%
28%	Luxury / Sin Goods	Air Conditioners, Cars, Tobacco, Aerated Drinks, Casinos	14%+14%

💡 Tip: Some goods also attract Compensation Cess on top of 28% GST — e.g., luxury cars and tobacco products.

Who Should Use a GST Calculator?

Business Owners & Traders: Quickly calculate tax payable on sales/purchases and prepare accurate invoices.
Freelancers & Consultants: Add 18% GST on service invoices and find the exact amount to charge clients.
Accountants & CA Students: Cross-check GST calculations during audit or filing.
Shoppers & Consumers: Understand how much GST you're actually paying on products.
Govt Exam Aspirants: For GK sections in MPSC, UPSC, Banking, Railways exams.
E-Commerce Sellers: Correctly compute tax on Amazon, Flipkart, Meesho listings.

GST Registration — When is it Mandatory?

Annual turnover exceeds ₹40 lakh for goods (₹20 lakh for services)
Annual turnover exceeds ₹20 lakh in special category states
You supply goods/services across states (inter-state)
You sell through an e-commerce platform
You are required to pay tax under reverse charge mechanism

GST vs Old Tax System

Parameter	Before GST	After GST
Number of Taxes	17+ (VAT, Service Tax, Excise…)	1 (GST with 4 slabs)
Tax-on-Tax (Cascading)	Yes	No (Input Tax Credit)
Transparency	Low	High
Cross-State Trade	Complex (CST + Octroi)	Simple (IGST)

Frequently Asked Questions (FAQs)

What is the full form of GST?

GST stands for Goods and Services Tax. It was implemented in India on 1st July 2017 under the "One Nation, One Tax, One Market" initiative.

Difference between CGST, SGST, and IGST?

CGST goes to the Central Government, SGST to the State Government (both for intra-state). IGST applies to inter-state transactions and goes entirely to the Central Government before being distributed.

How do I calculate GST on ₹50,000 at 18%?

GST = (50,000 × 18) ÷ 100 = ₹9,000. Total = ₹59,000. CGST = ₹4,500, SGST = ₹4,500. Simply enter ₹50,000 and select 18% in our calculator above.

What is Input Tax Credit (ITC)?

ITC allows businesses to deduct the GST paid on purchases from the GST collected on sales, eliminating the cascading tax-on-tax effect of the old system.

What GST rate applies to restaurants?

Most restaurants charge 5% GST (no ITC). AC restaurants in hotels with room tariff above ₹7,500 may charge 18% GST. Outdoor catering is taxed at 18% with ITC.

Is this GST Calculator free to use?

Yes, 100% free. No login, registration, or subscription required. Use it unlimited times from any device.

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