Calcula is the calculator for GST, cost, sell, margin, cash notes and number words. Built for Shops, students and anyone who works with money — in English, Hindi or Punjabi. Everything runs on the phone. No internet. No storage permission.

WHO IT IS FOR
Shopkeepers, traders, accountants, students and home users who need a fast pad for tax, cash and everyday sums — not a spreadsheet.

BUSINESS / GST
The Business pad is made for the counter.
• GST 5%, 12%, 18% and 28% — TAX+ to add tax, TAX− to take it out
• Discount, commission and markup
• Cost, sell and margin — each key closes the number, like + or =
• Quantity × rate, grand total, cash change and round up
• Send a total to Notes in one tap
• For India the pad says GST. For other countries it says TAX

NOTES — COUNT THE DRAWER
Count notes : 500, 200, 100, 50, 20, 10, 5, 2, 1. Set an expected total and see match, surplus or shortage. Built for closing the till.

WORDS — NUMBERS IN LANGUAGE
Type an amount and get it in words.
• Indian system: thousand, lakh, crore
• International: million, billion, trillion
• Currency words follow the country you pick (rupees and paise, dollars and cents, and more)
Copy the result for cheques, invoices or WhatsApp.

CALCULATOR
• Basic pad with live preview and percent
• Scientific: sin, cos, tan, powers, roots, log, ln, n!, π, e — DEG or RAD
• Decimal places 0–6
• History of full expressions — tap a line to restore and edit
• Sample sums in More so you can learn each key

OFFLINE TOOLS
Age, unit conversion (metric or country units), date difference, area, volume, BMI, fuel, time, speed, percent, discount, simple interest, compound interest and loan EMI. Copy or share interest and EMI schedules as text. No live currency rates — those need the internet, so they are not here.

LOOK AND LANGUAGE
• English, Hindi (हिन्दी) and Punjabi (ਪੰਜਾਬੀ)
• Country and currency: India, US, UK, Eurozone, UAE, Saudi Arabia, Pakistan, Bangladesh, Nepal, Sri Lanka and many more
• Themes: Business, Dark, Light, Neon, Gold, Leather, Wood, Steel, 3D Press, Segment, Candy and mixes
• Key and result size S / M / L / XL
• Optional keep-screen-awake, or follow the phone timeout
• Last tab, memory, notes, history and settings stay on the device

PRIVACY
Calcula does not read photos, downloads or the SD card. Nothing is stored outside the app. No account. Works fully offline.

Open Calcula. Type 1500, tap 18%, then TAX+. That is GST on the counter — in three taps.