How do I calculate GST at 18% on ₹1 lakh?

GST at 18% on ₹1,00,000: GST amount = ₹18,000. Total = ₹1,18,000. For intra-state: CGST = ₹9,000 and SGST = ₹9,000. For inter-state: IGST = ₹18,000.

When should I use Intra-State vs Inter-State?

Choose Intra-State if the supplier and buyer are in the same Indian state — GST splits into CGST and SGST. Choose Inter-State for transactions between different states — the full GST is collected as IGST. The total tax amount is the same either way; only the tax account differs.

Is this calculator accurate for GST return filing?

This tool is for quick estimation, invoice preparation, and learning. For actual GST return filing, verify with a Chartered Accountant or the official GSTN portal (gst.gov.in), as rates can change through GST Council notifications.

What is the GST rate on mobile phones in India?

Mobile phones attract 18% GST in India. On a phone priced at ₹15,000 excluding GST: GST = ₹2,700, final consumer price = ₹17,700.

Is GST charged on exports from India?

No. Exports are zero-rated under GST, meaning the tax rate is 0% and the exporter can claim a refund of all input tax credits. Exporters file a Letter of Undertaking (LUT) to export without paying IGST upfront.

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INDIA GST FINANCE TOOL

GST Calculator

🇮🇳 India's most complete GST calculator — add or remove GST, get CGST / SGST / IGST breakdown, build bulk invoices, and explore rates for 50+ goods.

✅ 100% Free🔓 No Login Required🧾 Bulk Invoice Export

All 5 GST Slabs

CGST + SGST / IGST Split

50+ Goods Rate Guide

GST Details

Mode

Base Amount (excl. GST)₹10,000.00

₹

GST Rate

Transaction Type

Same state — GST splits equally into CGST + SGST

Adding 18% GST to ₹10,000

Base Amount (excl. GST)₹10,000.00

Total GST @ 18%₹1,800.00

CGST + SGST Breakdown (Intra-State)

CGST (9%)₹900.00

SGST (9%)₹900.00

Total (incl. GST)₹11,800.00

Effective GST on total price15.25%

🔧 How It Works

India's most complete GST calculator — from basic tax to bulk invoices, all in one place

Enter Amount & Rate

Type the price and choose from India's official GST slabs — 0%, 5%, 12%, 18%, or 28% — then pick Add or Remove GST mode.

Choose Transaction Type

Select Intra-State to get the CGST + SGST split, or Inter-State to see the full IGST amount — instantly calculated.

Build Invoice or Explore Rates

Switch to Bulk Invoice to add multiple line items and export a full GST invoice, or browse the Rates Guide for 50+ common goods.

UNDERSTAND GST

Everything You Need to Know About GST in India

Whether you're a business owner, CA student, or curious consumer —understanding how GST works helps you make smarter financial decisions.

What Is GST?

Goods and Services Tax (GST) is a comprehensive indirect tax levied on the supply of goods and services across India. Introduced on 1 July 2017, it replaced a fragmented system of over a dozen central and state taxes — including VAT, service tax, excise duty, and octroi — with a single unified tax structure under the principle of "One Nation, One Tax."

GST is a consumption-based tax, meaning it is borne by the final consumer. Each business in the supply chain collects GST from its buyer, pays GST to its supplier, and remits only the difference (input tax credit) to the government. This eliminates the cascading effect of the old tax-on-tax system and makes the final price more transparent.

India operates a dual GST structure: the Central Government levies CGST and the State Government levies SGST on intra-state transactions. For inter-state supply, the Centre collects IGST which is subsequently shared with the destination state.

GST Calculation Formula — Step by Step

➕ Adding GST to a Base Price

Use this when you have the pre-tax price and want to find the customer-facing price.

GST Amount = Base Price × (Rate ÷ 100)

Total = Base Price + GST Amount

Example: ₹10,000 + 18% = ₹1,800 GST → ₹11,800

➖ Removing GST from an Inclusive Price

Use this when you have the GST-inclusive price and need to find the base amount and tax component.

Base = Inclusive Price ÷ (1 + Rate ÷ 100)

GST = Inclusive Price − Base

Example: ₹11,800 ÷ 1.18 = ₹10,000 base → ₹1,800 GST

CGST vs SGST vs IGST — The Complete Breakdown

India's dual GST structure means the same transaction caninvolve different tax accounts depending on whether the buyer and seller are in the same state.

🏛️ Intra-State Transaction (Same State)

GST is split equally between CGST (Central) and SGST (State). On an 18% rate: CGST = 9%, SGST = 9%. Both amounts are the same; they go to different accounts.

🌐 Inter-State Transaction (Different States)

The full 18% is collected as IGST by the Centre. The destination state later receives its share via a settlement mechanism. The total GST amount paid by the buyer is identical — only the accounting differs.

📦 Import Transactions

Imports are treated as inter-state supply, so IGST applies. Additionally, Basic Customs Duty (BCD) is levied before IGST calculation, making IGST on imports = (CIF value + BCD) × IGST rate.

Input Tax Credit (ITC) — How Businesses Benefit

Input Tax Credit is the most powerful feature of GST. Registered businesses can offset the GST they pay on purchases (input tax) against the GST they collect on sales (output tax), remitting only the net difference.

ITC Example:

Manufacturer buys raw materials: pays ₹1,800 GST

Sells finished goods: collects ₹3,600 GST

Net GST payable = ₹3,600 − ₹1,800 = ₹1,800

This eliminates the cascading "tax on tax" problem of the old system. The government only receives tax on the value added at each stage, making the system fundamentally more efficient. ITC claims are matched electronically via GSTR-2B, making accurate invoicing critical.

WORKED EXAMPLES

GST Calculation Examples for Common Scenarios

Real-world examples covering the most common situations you'llencounter — from buying a phone to raising a service invoice.

18% GST — Intra-State

Mobile Phone Purchase

You're buying a smartphone priced at ₹25,000 (excl. GST). What's the final price?

Base Amount₹25,000

GST (18%)₹4,500

Total₹29,500

CGST ₹2,250 + SGST ₹2,250

18% GST — Inter-State

IT Services Invoice

A freelance developer invoices a client ₹50,000 for software development. Client and developer are in different states.

Base Amount₹50,000

GST (18%)₹9,000

Total₹59,000

IGST ₹9,000 (inter-state)

5% GST — GST Inclusive (Remove)

Restaurant Bill

Your restaurant bill (AC establishment) shows ₹1,180 as total. How much GST did you pay?

Base Amount₹1,123.81

GST (5%)₹56.19

Total₹1,180.00

CGST ₹28.10 + SGST ₹28.10

28% GST — Intra-State

New Car Purchase

A mid-size SUV has an ex-showroom price of ₹15,00,000. What is the GST component?

Base Amount₹15,00,000

GST (28%)₹4,20,000

Total₹19,20,000

CGST ₹2,10,000 + SGST ₹2,10,000

3% GST — Intra-State

Gold Jewellery

You're buying gold jewellery worth ₹2,00,000 (excl. GST). Special 3% slab applies.

Base Amount₹2,00,000

GST (3%)₹6,000

Total₹2,06,000

CGST ₹3,000 + SGST ₹3,000

5% GST — Intra-State

Under-Construction Flat

Buying an under-construction apartment for ₹45,00,000. GST applies at the 5% affordable housing rate.

Base Amount₹45,00,000

GST (5%)₹2,25,000

Total₹47,25,000

CGST ₹1,12,500 + SGST ₹1,12,500

WHO USES THIS TOOL

Built for Every Indian Business and Consumer

From solo freelancers to enterprise finance teams, this GST calculator handles the full spectrum of Indian GST calculation needs.

Retail & E-Commerce Sellers

D2C brands, Amazon/Flipkart sellers, and retail store owners use this to quickly price products inclusive of GST, verify the tax component on invoices, and ensure correct GST charging to customers.

Businesses & Freelancers

IT professionals, consultants, agencies, and service providers calculate GST on their invoices before raising them to clients. The bulk invoice tab lets you build a complete multi-item bill in seconds.

Accountants & Finance Teams

CA firms, finance departments, and bookkeepers use the CGST/SGST/IGST split feature to prepare journal entries, verify vendor invoices, and reconcile GST amounts before GSTR filing.

Importers & Exporters

Businesses engaged in inter-state trade or exports need to correctly identify whether IGST or CGST+SGST applies. This tool's transaction type toggle makes that distinction clear and instant.

Students & CA Aspirants

Commerce and CA students studying indirect taxation use this to verify textbook calculations, practice GST problems, and understand the mechanics of inclusive vs exclusive pricing.

Consumers & Smart Buyers

When buying electronics, vehicles, or real estate, everyday consumers use this to verify whether a quoted price is GST-inclusive, understand how much tax they're actually paying, and compare true costs.

COMMON MISTAKES

GST Calculation Errors to Avoid

These mistakes trip up even experienced business owners. Knowing them helps you avoid costly errors on invoices and returns.

1Applying GST on GST (Cascading)

The most common error: computing GST on a value that already includes another tax. For example, charging 18% GST on a value that already includes TCS/TDS. GST should always be applied to the pure base value of goods or services.

❌ Wrong: ₹10,000 + 5% TCS = ₹10,500 → GST on ₹10,500
✓ Right: GST applied on ₹10,000, TCS calculated separately

2Confusing Inclusive vs Exclusive Pricing

Quoting ₹10,000 "inclusive of GST" is very different from ₹10,000 "plus 18% GST." The former means the customer paysexactly ₹10,000; the latter means they pay ₹11,800. Always specify clearly on quotes and invoices.

Exclusive (add GST): ₹10,000 + 18% = ₹11,800 total
Inclusive (remove GST): ₹10,000 → base ₹8,474.58 + GST ₹1,525.42

3Using the Wrong GST Slab

Many goods have rate conditions — clothing under ₹1,000 is taxed at 5% but above ₹1,000 it's 12%. Footwear has similar thresholds. Using a flat rate without checking the value-based conditions leads to under- or over-charging.

Use the GST Rates Guide tab in this calculator or the official GSTN portal to verify the correct slab for your specific goods before raising invoices.

4Wrong CGST/SGST vs IGST Classification

Misclassifying an inter-state transaction as intra-state (or vice versa) means the tax goes to the wrong government account. This requires a credit note/debit note correction and can attract scrutiny during GSTR reconciliation.

The rule is simple: check the Place of Supply (POS). If POSmatches the supplier's state → CGST + SGST. If different → IGST. This calculator's transaction type toggle correctly handles this distinction.

Learn More — From Our Blog

In-depth guides on GST, invoicing, and Indian taxation.

How to Calculate GST in India — Complete Guide

Formulas, examples, CGST/SGST/IGST explained, and a walkthrough of every GST slab with practical scenarios.

Read Guide

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Calculate your monthly EMI for home loans, car loans, and personal loans. GST applies to processing fees too.

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Frequently Asked Questions

Everything you need to know about GST calculation in India

What is GST and how is it calculated?

GST (Goods and Services Tax) is India's unified indirect tax on the supply of goods and services. To add GST: GST Amount = Base Price × (GST Rate / 100), Total = Base + GST. To remove GST from an inclusive price: Base = Price ÷ (1 + Rate/100), GST = Price – Base.

What is the difference between CGST, SGST, and IGST?

For intra-state transactions (within the same state): GST is split equally into CGST (Central GST) and SGST (State GSst), both levied at half the applicable rate. For inter-state transactions (between two states): The full GST is collected as IGST (Integrated GST) by the central government and later distributed to the destination state.

What are the GST slabs in India?

India has five main GST slabs: 0% (essential goods — fresh food, healthcare, education), 5% (basic necessities — budget clothing, transport), 12% (standard goods — packaged food, footwear under ₹1,000), 18% (most services & electronics — mobile phones, laptops, telecom), and 28% (luxury & sin goods — cars, ACs, tobacco, aerated drinks). Some items like gold (3%) and diamonds (0.25–1.5%) have special rates.

How do I use the Bulk Invoice Calculator?

Switch to the Bulk Invoice tab, add each product with its name, quantity, unit price, and applicable GST rate. The tool automatically computes taxable value, GST amount, and row total for each item. You can then copy the full invoice summary to clipboard or download it as a .txt file.

When should I choose Intra-State vs Inter-State?

Choose Intra-State if the supplier and buyer are in the same Indian state — your GST will split into equal CGST and SGST. Choose Inter-State if the transaction crosses state boundaries — the entire GST is collected as a single IGST. When filing returns, this distinction determines which government account the tax goes to.

Is this calculator accurate for filing GST returns?

This tool is designed for quick estimation, learning, and invoice preparation. For actual GST return filing, always verify with a Chartered Accountant or the official GSTN portal (gst.gov.in), as rates can change through GST Council notifications.

Is my data sent to any server?

No. All calculations happen entirely in your browser using JavaScript. Your figures never leave your device and are never stored, logged, or transmitted anywhere.