What is the difference between CGST, SGST and IGST?

CGST (Central GST) and SGST (State GST) apply to intra-state transactions — half of the GST goes to the central government and half to the state. IGST (Integrated GST) applies to inter-state transactions — the entire amount is collected by the central government and later shared with the destination state.

How do I calculate GST on an amount?

To add GST: GST amount = base × rate%, total = base + GST. For example, ₹10,000 at 18% gives ₹1,800 GST and a ₹11,800 total. To remove GST from an inclusive total: base = total ÷ (1 + rate%). For example, ₹11,800 at 18% gives a base of ₹10,000 and GST of ₹1,800.

How does GSTBox calculate CGST and SGST?

For intra-state transactions, GSTBox splits the total GST equally into CGST and SGST. For example, on 18% GST it shows 9% CGST and 9% SGST. For inter-state transactions it shows the full amount as IGST. The split is automatic when you select the transaction type.

Yes — GSTBox is completely free. No signup, no email, no premium tier. The calculator runs entirely in your browser.

Do you store the amounts I enter?

No. All calculation happens locally in your browser. Nothing you type is sent to any server. You can verify this in your browser's DevTools — opening Network and clicking around the calculator produces zero requests.

Can I use GSTBox for invoice GST calculations?

Yes. Use the 'Add GST' mode for invoice creation (where you start with the net amount and add GST), or 'Remove GST' for back-calculation (where you have an inclusive total and need to break it down). Click Copy to paste the breakdown directly into your invoice software.

What other tools does GSTBox offer?

10 tools are live: GST Calculator, Income Tax Calculator (FY 2026-27), EMI Calculator, TDS Calculator (Sections 194C/J/H/I/IB/IA/A/Q/O), GST Late Fee + Interest Calculator, HRA Exemption Calculator, Free GST Invoice Generator, Capital Gains Calculator (post-Budget 2024 LTCG/STCG), Contract Templates (NDA / Freelance / Employment), and Email Signature Generator. All free, all browser-based, no signup.

Free GST Calculator for India

Calculate CGST, SGST and IGST on any amount in seconds. Built for Indian businesses, freelancers, and CAs.

100% free No signup Works in your browser

Amount In rupees

₹

GST rate Pick a slab or enter custom

Transaction type

Intra-state CGST + SGST Inter-state IGST

Net amount ₹ 0.00

GST ₹ 0.00

CGST ₹ 0.00

SGST ₹ 0.00

IGST ₹ 0.00

Total ₹ 0.00

More tools, all free

Everything you need to run a small business in India — calculators, generators, and templates.

GST Calculator

CGST, SGST, IGST with all standard rates.

Live

Income Tax Calculator

Old vs. new regime, FY 2026-27.

Live

EMI Calculator

Home, car, personal, education loans.

Live

TDS Calculator

194C, 194J, 194I, 194H, and more.

Live

GST Late Fee & Interest

GSTR-3B/1/9 late filing fee + 18% interest.

Live

HRA Calculator

Section 10(13A) least-of-3 exemption.

Live

Invoice Generator

Free GST invoice with print-to-PDF.

Live

Capital Gains Calculator

LTCG / STCG with indexation.

Live

Contract Templates

NDA, freelance, employment.

Live

Email Signature

Photo + logo + socials, copy to Gmail/Outlook.

Live

Frequently asked questions

Everything you need to know about GST and how this calculator works.

What is GST in India?

GST (Goods and Services Tax) is a unified indirect tax that came into effect on 1 July 2017, replacing VAT, service tax, excise, and several other central and state taxes. It applies to most goods and services sold in India.

Most items fall into one of five slabs: 0%, 5%, 12%, 18%, 28%. Some categories (like luxury cars and tobacco) also attract a compensation cess on top.

What's the difference between CGST, SGST, and IGST?

CGST + SGST apply to intra-state transactions. The GST is split equally — half goes to the central government (CGST), half to the state (SGST). On 18% GST, you'd see 9% CGST + 9% SGST.

IGST applies to inter-state transactions. The full amount is collected by the central government and later shared with the destination state.

Tip: when in doubt, your billing party's state vs. yours determines the type. Same state → CGST+SGST. Different state → IGST.

How do I calculate GST on a price?

Adding GST (exclusive amount):

GST = base × rate / 100
Total = base + GST

Example: ₹10,000 at 18% → GST = ₹1,800, Total = ₹11,800.

Removing GST (inclusive amount):

Base = total ÷ (1 + rate / 100)

Example: ₹11,800 incl. 18% → Base = ₹10,000, GST = ₹1,800.

What are the current GST rates in India (2026)?

As of 2026 the main GST slabs are:

0% — essential goods (fresh produce, milk, books for schools).
5% — basic essentials and some services (transport, low-cost garments).
12% — packaged foods, some services, computers.
18% — most services and many goods (the default).
28% — luxury and sin goods (cars, ACs, tobacco).

Some categories attract a compensation cess in addition to GST. Always check the official rate notification for your specific HSN/SAC code.

Is GSTBox free?

Yes — completely free. No signup, no premium tier, no email capture. The calculator runs entirely in your browser.

Do you store what I enter?

No. Calculation happens locally on your device. Nothing you type leaves your browser — verifiable by opening DevTools → Network and watching for zero requests as you use the calculator.

Can I use GSTBox for invoices?

Yes. Use Add GST mode when creating an invoice (you start with the net amount). Click Copy breakdown to paste the line items directly into your invoice software, email, or Tally / Vyapar entries.

A dedicated Invoice Generator with downloadable PDF templates is on the way — see the Tools section above.

What's the difference between this and Tally / Vyapar / Zoho Books?

Tally, Vyapar, and Zoho Books are full accounting platforms — they store your customers, inventory, and books. GSTBox is a free quick calculator for one-off GST math, plus simple business templates. Use GSTBox alongside your accounting software, not instead of it.