GST 2.0 slabs 0% · 5% · 18% · 40% from 22 Sep 2025Special rates 0.25% & 3% stones · precious metalsLate fee ₹50/day ₹20/day for nil returnsLate-fee cap ₹2,000 – ₹10,000 by turnoverInterest 18% p.a. on tax paid lateIntra-state CGST + SGST split equallyInter-state IGST full rateGSTIN 15 characters with a check digitGST 2.0 slabs 0% · 5% · 18% · 40% from 22 Sep 2025Special rates 0.25% & 3% stones · precious metalsLate fee ₹50/day ₹20/day for nil returnsLate-fee cap ₹2,000 – ₹10,000 by turnoverInterest 18% p.a. on tax paid lateIntra-state CGST + SGST split equallyInter-state IGST full rateGSTIN 15 characters with a check digit
bydigitalGST Tools
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GST calculators

🧮GST CalculatorAdd or remove GST with the CGST, SGST or IGST split.🔄Reverse GST CalculatorFind the base price and tax inside a GST-inclusive amount.⏰GST Late Fee & Interest CalculatorLate fee and 18% interest for a delayed GSTR-3B or GSTR-1.📈GST Profit Margin CalculatorCost price to selling price with margin, GST and cess.🔎GSTIN ValidatorCheck a GSTIN’s format, checksum, state and PAN.

Invoices & billing

🧾GST Invoice GeneratorA GST-ready tax invoice with auto totals, saved as PDF.📋Quotation MakerProfessional GST quotations with logo, bank details and terms.📒Billbook ToolBills, party book, numbering and balance tracking on your device.

GST guides

📘GST 2.0 explainedThe 5%, 18% and 40% slabs and what changed.📘How to calculate GSTAdd and remove GST formulas with examples.📘CGST vs SGST vs IGSTWhich tax applies within and across states.📘GST invoice rulesMandatory fields, copies and time limits.📘Quotation vs invoice vs proformaWhen to use each document.
All 8 tools are free, need no sign-up and run in your browser.Who builds bydigital →
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About bydigital

Free GST calculators and billing tools for India, built by Mantu Kumar and checked against the published GST rules.

What bydigital is

bydigital.in is a free set of GST calculators and billing tools for Indian freelancers, shop owners, traders, students and small businesses. Everything runs in your browser: there is no account to create, nothing to install and nothing you type is uploaded.

The name is written as one word, bydigital, though many people search for it as “By Digital”. Both lead here.

Who runs it

bydigital is built and maintained by Mantu Kumar and operated by Universal Hospitality, a business based in Navi Mumbai, Maharashtra, that builds free browser-based tools. Mantu has run small online businesses in India for years, so the tools started as answers to his own questions: what is 18% on this amount, what is the base price inside this MRP, how much late fee is due on a delayed GSTR-3B, and is this supplier’s GSTIN even valid?

The eight tools

Alongside the tools, the guides explain GST 2.0, how to calculate GST, CGST, SGST and IGST, invoice rules and quotations, invoices and proformas.

Private by design

Every calculation, invoice, quotation and GSTIN check is processed by JavaScript on your own device. The Billbook keeps its data only in your browser’s storage. Because nothing is stored on a server, we cannot recover a document for you, so always save the PDF.

How the numbers are checked

Each formula is written from the published rules (the CGST Act, GST Council decisions and CBIC notifications) and tested against worked examples before it goes live: for example, ₹10,000 at 18% must give ₹900 CGST + ₹900 SGST, and ₹11,800 including 18% must give a base of ₹10,000. When rates or caps change, the tools and guides are updated together. The full process is on the editorial policy page.

What bydigital is not

bydigital is not a chartered accountant, a GST Suvidha Provider or a government website, and it is not affiliated with GSTN or CBIC. Results are estimates and templates for convenience. For filing, notices, classification questions or anything with money at stake, confirm on gst.gov.in or with a CA.

How the site is funded

The tools are free. The site shows Google AdSense advertising and accepts optional donations. Advertisers and donors have no influence on any calculation or guide.

Contact

Found a wrong number, a bug or a tool you need? Write to [email protected] or use the contact page.

Mantu Kumar, founder of bydigital

Written and maintained by Mantu Kumar

Mantu runs small online businesses from Navi Mumbai and built bydigital for the GST sums he needed every week. He checks each calculator against the CGST Act, GST Council decisions and worked examples. He is not a chartered accountant, so results are estimates and the pages tell you when to confirm with one.

Read Mantu’s profile