GST Calculator
Add or remove GST from any amount — with full CGST, SGST & IGST breakdown.
GST Calculator – Complete Guide to Goods & Services Tax
The Goods and Services Tax (GST) is one of the most transformative tax reforms in India's financial history. Introduced on July 1, 2017, GST replaced a complex web of central and state taxes — including VAT, service tax, excise duty, and octroi — with a single, unified indirect tax system. Understanding and calculating GST accurately is critical for businesses, accountants, freelancers, and even regular consumers. Arattai.it.com's free GST Calculator simplifies this entire process in seconds.
What is GST?
GST stands for Goods and Services Tax. It is a destination-based, multi-stage, comprehensive indirect tax levied on the supply of goods and services in India. The tax is collected at each stage of the supply chain, but the final burden falls on the end consumer. GST operates on the principle of "one nation, one tax," creating a uniform tax structure across all Indian states and union territories.
GST is divided into three components: CGST (Central GST), SGST (State GST), and IGST (Integrated GST). For intra-state transactions, CGST and SGST are levied equally. For inter-state transactions, IGST is levied — which combines both CGST and SGST into a single integrated tax.
GST Slabs in India
India's GST structure consists of four primary tax slabs:
- 0% (Nil Rated): Essential items like fresh milk, vegetables, eggs, and educational services.
- 5%: Household necessities like packaged food, footwear under ₹1000, economy hotels, and rail/air travel.
- 12%: Processed foods, business class air travel, mobile phones, and computers.
- 18%: The most common slab covering services like restaurants, telecom, financial services, IT services, and most manufactured goods.
- 28%: Luxury goods, cars, tobacco, casinos, and race clubs.
How to Calculate GST
Adding GST to an Amount
To find the total price including GST: Total = Original Amount × (1 + GST Rate / 100). For example, if a product costs ₹10,000 and GST is 18%, Total = ₹10,000 × 1.18 = ₹11,800. The GST amount is ₹1,800 (CGST = ₹900, SGST = ₹900).
Removing GST from an Amount (Reverse GST)
To find the original price before GST from a GST-inclusive amount: Original = Total / (1 + GST Rate / 100). If you paid ₹11,800 inclusive of 18% GST, the base price was ₹11,800 / 1.18 = ₹10,000.
CGST vs SGST vs IGST
When GST applies to an intra-state sale (within the same state), it is split equally between CGST (going to the central government) and SGST (going to the state government). For an 18% GST rate, CGST = 9% and SGST = 9%. For inter-state sales, IGST = 18% is collected by the central government and later distributed to the destination state.
Who Needs to Register for GST?
Any business with an annual turnover exceeding ₹40 lakhs (₹20 lakhs for special category states, ₹10 lakhs for certain services) must register for GST. Additionally, businesses involved in inter-state supply, e-commerce operators, and those making supplies on behalf of others also require mandatory registration regardless of turnover.
Input Tax Credit (ITC)
One of GST's most significant advantages is the Input Tax Credit mechanism. Registered businesses can claim credit for the GST they've paid on purchases, reducing their final tax liability. This eliminates the cascading effect of taxes and ultimately reduces the cost burden on the end consumer.
GST Filing and Compliance
GST-registered businesses must file returns monthly, quarterly, or annually depending on their turnover and scheme. The main return forms are GSTR-1 (outward supplies), GSTR-3B (monthly summary), and GSTR-9 (annual return). Late filing attracts penalties and interest, making accurate calculation tools like ours essential.
Why Use Arattai.it.com GST Calculator?
Our tool gives you instant results — no need to memorize formulas or fumble with spreadsheets. Simply enter your amount, choose the GST slab (5%, 12%, 18%, or 28%), and toggle between "Add GST" or "Remove GST." The calculator immediately shows the base amount, GST amount, CGST, SGST, and total amount. It's built for business owners, accountants, shoppers, and freelancers alike.