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

CGST and SGST apply to intra-state transactions — each is half the total GST rate. IGST applies to inter-state transactions at the full rate. For example, 18% GST within a state = 9% CGST + 9% SGST. Between states = 18% IGST.

How do I remove GST from an inclusive price?

Use the formula: GST Amount = Total Price minus [Total Price x 100 divided by (100 + GST Rate)]. For example, to remove 18% GST from Rs.1,18,000: GST = Rs.18,000. Select Remove GST (Inclusive) on gstcalculator.me.

What are the GST rate slabs in India?

India has five main GST slabs: 0% (essential goods), 5% (basic necessities), 12% (processed goods), 18% (most goods and services), and 28% (luxury and sin goods). Gold and silver attract 3%.

What is the GST registration threshold for goods?

Businesses with an annual turnover of ₹40 lakh or more need to register for GST. Goods suppliers above this threshold must register.

What is the GST registration threshold for services?

Service providers with an annual turnover of ₹20 lakh or more need to register for GST. This is lower than the goods threshold.

What is the GST Composition Scheme?

Businesses with turnover up to ₹1.5 Cr (goods) or ₹75 lakh (services) can opt for the simplified Composition Scheme and pay flat GST rates with quarterly filing instead of monthly, reducing compliance burden.

Who needs to file e-invoicing?

E-invoicing is mandatory for businesses with turnover above ₹5 Cr from FY 2023-24. It integrates directly with the GST portal for better tracking and reduced fraud.

What are the main GST slabs in India?

India has 5 main GST slabs: 0% (nil rate on essentials), 5% (essential goods/services), 12% (standard rate I), 18% (standard rate II - most common), and 28% (luxury goods). Different products fall into different slabs based on their nature.

Reminder: GSTR-3B for last month is due by the 20th. Late filing attracts ₹50/day (₹20/day for nil returns).

GST Calculator India — Free Online CGST, SGST & IGST Calculator

Instant GST computation for all slabs (5%, 18%, 40% under GST 2.0) — add or remove GST, no login needed

Enter Amount & GST Details

Amount (₹)

₹

Select GST Slab

Calculation Mode

Transaction Type

Total Amount Payable

₹11,800

Includes 18% GST on ₹10,000

Base Amount₹10,000

CGST(9%)₹900

SGST(9%)₹900

Total Payable₹11,800

📲 Share this calculation

*GST Calculation*
Base: ₹10,000
GST 18%: ₹1,800
Total: ₹11,800

Calculated at gstcalculator.me

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Two key returns: GSTR-1 (sales, due 11th) reports invoices. GSTR-3B (due 20th) is the summary where you pay tax. Both are mandatory.

📋 GST Slab Reference Guide

Nil RateEssential food grains, fresh milk, vegetables, fruits, eggs, salt, books, health & life insurance (GST 2.0)

Essential RatePackaged foods, medicines, bicycles, textiles ≤₹2,500, footwear ≤₹1,000, transport services, small restaurants

18%

Standard Rate (Most common)Electronics, AC restaurants, most services (IT, telecom, financial), vehicles ≤350cc, small/mid cars, cement

40%

Luxury / Sin Rate (GST 2.0)Tobacco, pan masala, caffeinated aerated drinks, high-end SUVs >2500cc, yachts, private aircraft

⚠️ GST Registration Thresholds

Goods

₹40L

Annual turnover

Services

₹20L

Annual turnover

Composition Scheme: Businesses up to ₹1.5 Cr (goods) / ₹75L (services) can opt for simplified quarterly filing at lower flat rates.

E-invoicing mandatory for turnover above ₹5 Cr from FY 2023-24.

What Is This GST Calculator?

This is a free online GST calculator for India that instantly computes Goods and Services Tax for any amount at any slab — 0%, 5%, 18%, or 40% (GST 2.0 rates, effective September 22, 2025). It works both ways: add GST to a base price (GST-exclusive) or remove GST from a total (GST-inclusive, also called reverse GST calculation). Every result shows the CGST and SGST split for intra-state transactions or the single IGST amount for inter-state transactions — exactly as they must appear on a GST invoice.

Unlike calculators from Zoho, ClearTax, or TaxAdda, this tool requires no login, no signup, and has no paid upsell. It is built for CAs, accountants, freelancers, and e-commerce sellers who need quick, accurate GST arithmetic dozens of times a day.

How to Calculate GST — The Formulas

Adding GST (exclusive): GST Amount = (Original Cost × GST Rate) ÷ 100. Example: 18% GST on ₹1,000 = ₹180, so the total payable is ₹1,180.

Removing GST (inclusive / reverse): GST Amount = Total Price − [Total Price × 100 ÷ (100 + GST Rate)]. Example: from a GST-inclusive price of ₹1,180 at 18%, the GST portion is ₹180 and the base price is ₹1,000.

For intra-state sales the GST splits equally: 18% becomes 9% CGST + 9% SGST (₹90 + ₹90 in the example above). For inter-state sales the full 18% applies as IGST (₹180). Read the full guide on how to calculate GST in India or the explainer on CGST vs SGST vs IGST.

GST Calculator — Frequently Asked Questions

Is this GST calculator free?

Yes — completely free with no login, no account, and no usage limits. It runs entirely in your browser; amounts you enter are never sent to a server.

How do I calculate 18% GST on an amount?

Multiply the amount by 0.18. On ₹1,00,000 that is ₹18,000 GST, making the total ₹1,18,000 — shown instantly above with the CGST/SGST or IGST split.

How do I remove GST from a price (reverse GST)?

Switch the calculator to inclusive mode. It applies the formula Base = Total × 100 ÷ (100 + rate) — e.g. ₹1,18,000 inclusive of 18% GST has a base of ₹1,00,000 and ₹18,000 tax.

Which GST rate should I use?

After GST 2.0 (September 2025): essentials are 0–5%; most services and electronics fall under 18%; luxury and sin goods (tobacco, aerated drinks, high-end SUVs) are 40%. The 12% and 28% slabs are abolished. See the GST rate slabs guide.

When do CGST/SGST apply instead of IGST?

If the supplier and place of supply are in the same state, GST splits into equal CGST and SGST halves. If they are in different states, the full rate applies as IGST.