English · Türkçe

Open the calculator · Get started · Calculation rules

Easy Calc

Everyday calculations, made simple. Percentages, discounts, increases and VAT in a focused interface, with instant answers.

Features

• Dark & light themes — switch at any time; your preference is remembered on your device.
• English and Turkish — opens in your browser's language; controls, results, errors and number formatting follow the language you pick, and your choice is remembered.
• Seven quick tools — percentage, discount, increase, percentage ratio, percentage change, add VAT and remove VAT.
• Classic calculator — operator precedence, parentheses, negative values and decimals, without eval.
• Less typing — preset rates, live results, copy to clipboard and reusable session history.
• Responsive & accessible — large touch targets, visible keyboard focus and labeled controls.
• Private by design — calculations run in your browser. No account or analytics; only theme and language preferences use local storage.

Changing theme or language preserves your current inputs and calculation history. History is held in memory and clears on refresh.

Getting started

Use Node.js 24.

git clone https://github.com/Talkdedsec/easy-calc.git
cd easy-calc
npm ci
npm run dev

Open the local URL printed in the terminal. On Windows, use npm.cmd if PowerShell blocks npm.ps1.

Checks & builds

npm run typecheck
npm run lint
npm test
npm run build

npm run build writes the static site to dist/; npm run preview serves it locally. GitHub Actions runs every check above and publishes each push to main; pull requests only run checks. For a fork, set Settings → Pages → Source → GitHub Actions and update the repository / social-preview URLs.

Calculation rules

Tool	Formula
Percentage	amount × rate / 100
Discount	amount × (1 − rate / 100)
Increase / add VAT	amount × (1 + rate / 100)
Remove VAT	inclusive amount / (1 + rate / 100)
Percentage ratio	part / whole × 100
Percentage change	(new − old) / old × 100

• The old value for percentage change must be positive; the whole for a ratio cannot be zero.
• In the classic calculator, % divides the preceding value by 100: 1000 × 20% = 200. 1000 + 20% = 1000.2. Use Increase to add a percentage to an amount.
• Decimal input accepts a dot or comma. Do not enter thousands separators: use 1234.56 or 1234,56.
• Output follows your language: 1,234.56 in English, 1.234,56 in Turkish.
• Rates are examples, not automatically selected tax rates.
• Results display up to eight decimal places. Standard JavaScript number precision applies.

Keyboard

Focus the classic expression field to type a calculation. Enter calculates; Esc clears. All buttons are reachable with Tab.

Project map

Path	Purpose
src/App.tsx	Calculator interface and saved preferences
src/design.css	Responsive light and dark themes
src/lib/i18n.ts	English / Turkish text and locale formatting
src/lib/math.ts	Arithmetic parser and calculation formulas
public/preferences.js	Applies the saved theme and language before first paint
public/banner.png	README banner and social preview
tests/	Math and localization checks
.github/workflows/pages.yml	Checks and GitHub Pages publishing