100% Free Client-Side Utilities

Free Commercial & Retail Business Calculators

Everyday accounting and tax calculations engineered specifically for Indian shopkeepers, wholesalers, restaurant operators, and independent merchants. Private, client-side, zero signup, and zero watermarks.

Instant Invoice & Thermal Receipt Maker

Draft GST-compliant A4 invoices or 58mm / 80mm thermal POS slips. Add line items, apply discounts, and print or export PDF instantly.

58mm / 80mm A4 Format Print / PDF
Open Invoice Maker →

Indian GST Calculator (Inclusive & Exclusive)

Calculate forward tax additions or extract reverse GST from MRPs across 0%, 5%, 12%, 18%, and 28% slabs with automated CGST/SGST/IGST division.

Reverse GST CGST / SGST 1-Click Copy
Open GST Calculator →

Retail Profit Margin vs. Markup Calculator

Determine true profit per sale. Compare cost-based markup against revenue-based gross margins and avoid dangerous promotional discounting errors.

Margin % Markup % Target Matrix
Open Margin Calculator →

Daily Cash Drawer & Note Tally (Rojmel)

Count currency notes across ₹500, ₹200, ₹100, and coin denominations. Balance drawer cash with UPI payments and flag end-of-day discrepancies.

₹500 to ₹10 Notes UPI Balancing WhatsApp Share
Open Cash Tally Tool →

Why Client-Side Computing Matters for Local Business Privacy

Most commercial accounting software today forces Indian business owners into rigid cloud subscriptions. Every customer telephone number, item price, and daily turnover figure is sent to remote corporate servers, where it is stored, analyzed, and frequently monetized.

The tools on this page demonstrate the alternative: Local-First, Zero-Trust Computing. When you calculate reverse GST or generate a thermal invoice above, the JavaScript mathematical engine executes entirely in your browser's local sandbox memory. Not a single rupee of your sales data or customer phone number touches our servers.

This is the engineering philosophy behind KhataOS: Empowering Indian retailers and individuals with enterprise-grade bookkeeping, POS billing, and encrypted personal asset tracking without internet dependency or data surveillance.

Take Your Entire Store Ledger 100% Offline

KhataOS is built specifically for low-end devices and unpredictable internet. Run full billing, print receipts, and manage customer credit without ever worrying about server outages.

Download KhataOS for Android & Desktop