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Free GST Calculator India 2026 — Add, Extract & Reverse

Calculate GST instantly on any amount. Supports all slabs — 0%, 5%, 12%, 18%, 28%. Get full IGST & CGST+SGST breakdown in seconds..

All GST Slabs Covered IGST & CGST+SGST Split Add, Extract & Reverse Modes Free — Forever

Enter the original price — GST will be added on top.

%
IGST
Inter-state
CGST + SGST
Intra-state
Enter an amount to see the GST calculation
Common GST Rates
  • Restaurant / Food delivery 5%
  • Medicines & pharma products 12%
  • Packaged food & beverages 18%
  • Electronics & mobile phones 18%
  • Automobiles & spare parts 28%
  • Books & newspapers 0%
  • Clothing (below Rs. 1000) 5%
  • Gold & jewellery 3%
IGST vs CGST+SGST

IGST applies on inter-state sales (selling to a buyer in a different state).

CGST + SGST applies on intra-state sales (both in same state). Each is half the total GST rate.

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Stop calculating GST manually

ERP Group auto-calculates GST on every invoice, reconciles returns, and files GSTR-1 in one click.

Add GST (Exclusive)

Enter your base price. The calculator adds the GST amount on top to give you the final invoice value.

Extract GST (Inclusive)

Enter a price that already includes GST. The calculator separates the base amount from the tax component.

Reverse Calculation

Enter a GST amount and rate to find the original taxable value and the total invoice amount.

Understanding GST

What is GST & How Does This Calculator Work?

Everything you need to know about India's Goods and Services Tax — and how our free calculator saves you time every day.

GST (Goods and Services Tax) is India's unified indirect tax system, introduced on 1st July 2017. It replaced over 17 different central and state taxes — including VAT, Service Tax, Central Excise Duty, and Entry Tax — into one comprehensive nationwide tax framework.

GST follows a "One Nation, One Tax" philosophy, meaning the same GST rate applies to a product or service regardless of which Indian state it is bought or sold in. This eliminates the cascading effect of multiple taxes and makes compliance transparent and digital through the GSTN portal.

💡 ERP Group's GST Calculator helps you compute GST instantly — whether you're preparing a sales invoice, checking an MRP price, or reconciling your monthly purchases. No formulas, no manual errors.

India currently has five main GST slabs: 0%, 5%, 12%, 18%, and 28%. Essential items like fresh vegetables and books are taxed at 0%, while luxury goods like premium cars attract a 28% rate plus additional cess.

Central GST
CGST

Levied by the Central Government on intra-state transactions. Always paired with SGST — each is half the total GST rate.

State GST
SGST

Collected by the State Government on intra-state sales. Combined with CGST, they equal the full applicable GST rate.

Integrated GST
IGST

Applied on inter-state transactions (sales between different states) and imports. IGST equals the full GST rate.

Step-by-Step Guide

How to Use the GST Calculator — 4 Simple Steps

Calculate GST in seconds — no formulas, no spreadsheets, no errors.

01

Choose Calculation Mode

Select Add GST for base price, Extract GST if price includes tax, or Reverse if you know the GST amount.

02

Enter Your Amount (₹)

Type the price in rupees. For Add mode, enter price before tax. For Extract, enter total including GST. For Reverse, enter the GST amount.

03

Select the GST Rate

Choose the applicable GST slab — 0%, 5%, 12%, 18%, or 28% — from the rate buttons. Refer to the common rates table if unsure.

04

Choose Supply Type & Calculate

Select IGST for inter-state or CGST+SGST for intra-state. Click "Calculate GST Now" for instant breakdown.

GST Formulas

GST Calculation Formulas Explained

Our calculator uses these standard formulas approved by the GST Council of India.

➕ Add GST (Exclusive)
GST Amount = (Price × GST%) ÷ 100
Final Price = Price + GST Amount

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

➖ Extract GST (Inclusive)
Base Price = Total × 100 ÷ (100 + GST%)
GST Amount = Total − Base Price

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

🔄 Reverse GST Calculation
Base Price = GST Amount × 100 ÷ GST%
Total Price = Base Price + GST Amount

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

GST Rate Reference

GST Rate Slabs in India 2026 — Complete Reference Table

Use this quick-reference table to find the correct GST slab for your product or service before calculating.

GST Slab Category Common Items / Services CGST SGST IGST
0% (Nil) Essential Goods Fresh fruits & vegetables, milk, eggs, bread, books, newspapers, bangles 0% 0% 0%
5% Necessities Packaged food, edible oils, clothing below ₹1000, footwear below ₹500, restaurant services 2.5% 2.5% 5%
12% Standard Goods Medicines & pharma products, butter, cheese, processed food, business class air tickets 6% 6% 12%
18% Most Goods & Services Electronics, mobiles, IT services, banking, telecom, insurance, hotels, restaurants (AC) 9% 9% 18%
28% Luxury / Sin Goods Automobiles, tobacco products, pan masala, aerated drinks, luxury watches, 5-star hotels 14% 14% 28%
3% Precious Metals Gold, silver, diamonds, jewellery, precious stones 1.5% 1.5% 3%
Got Questions?

Frequently Asked Questions About GST Calculator

Answers to the most common questions about GST calculation in India.

A GST Calculator is a free online tool that instantly computes the Goods and Services Tax on any amount. It is used by business owners, accountants, CA firms, freelancers, traders, and retailers across India to prepare accurate invoices, verify MRP prices, and calculate tax liabilities without manual formulas or spreadsheets.

IGST (Integrated GST) applies when goods or services are sold between two different states — inter-state transactions. CGST + SGST applies when the buyer and seller are in the same state — intra-state transactions. For a product with 18% GST: inter-state attracts 18% IGST; intra-state attracts 9% CGST + 9% SGST. The total tax amount remains the same — only the type and collection authority differs.

To calculate 18% GST on ₹10,000: GST Amount = ₹10,000 × 18% = ₹1,800. Final Invoice Value = ₹10,000 + ₹1,800 = ₹11,800. If intra-state: CGST = ₹900, SGST = ₹900. If inter-state: IGST = ₹1,800. Use our calculator above for instant results on any amount.

To extract GST from an MRP (GST-inclusive price), use the Extract GST mode. Formula: Base Price = Total Price × 100 ÷ (100 + GST Rate). For example, if MRP is ₹1,180 with 18% GST: Base Price = ₹1,180 × 100 ÷ 118 = ₹1,000. GST = ₹1,180 − ₹1,000 = ₹180.

India's GST system in 2026 has five main slabs: 0% for essential items (fresh food, books, medicines); 5% for necessities (packaged food, clothing below ₹1000); 12% for processed goods and pharma; 18% for most services and consumer goods (electronics, IT, banking, telecom); and 28% for luxury and sin goods (automobiles, tobacco, aerated drinks). Gold and precious metals attract a special 3% rate.

Yes, ERP Group's GST Calculator is 100% free with no hidden charges, no account creation, no login, and no credit card required. You can use it unlimited times for any amount, any GST rate, and any number of transactions. It works on all devices — desktop, tablet, and mobile.

Reverse GST calculation is used when you know the GST amount but need to find the original taxable value. For example, if your GST amount is ₹1,800 at 18%, the taxable value = ₹1,800 × 100 ÷ 18 = ₹10,000. Use the Reverse mode in our calculator — just enter the GST amount and rate to get the base price and total invoice value instantly.

ERP Group's GST accounting software auto-calculates CGST, SGST, and IGST on every invoice, handles e-invoicing and e-Way bills, reconciles GSTR-2A/2B, and files GSTR-1 and GSTR-3B directly — eliminating manual calculator use entirely. Over 5,000 Indian businesses use ERP Group for automated GST compliance. Book a free demo to see it in action.

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Join 5,000+ Indian MSMEs, CA firms & traders who use ERP Group to automate GST invoicing, GSTR filing, and accounting — saving 10+ hours every week.

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