EMI, GST, age, QR codes and more — fast, private tools that run entirely in your browser. No downloads, no cost, no account needed.
Pick a tool below — every tool is free and works on mobile and desktop.
Calculate monthly EMI, total interest and total payment for home, car or personal loans.
Add or remove GST (5%–28%) from any amount. Built for Indian businesses and shoppers.
Find your exact age in years, months and days from your date of birth.
Create QR codes for links, UPI payments, Wi-Fi passwords and plain text. Download as PNG.
Shrink JPG/PNG photos right in your browser before uploading or sharing. Private & fast.
Count words, characters, sentences and reading time as you type. Ideal for writers & students.
Create strong, random passwords with letters, numbers and symbols. One click to copy.
Convert length, weight, temperature, area and volume between metric and imperial units.
OpenCalculator is a collection of simple, fast and 100% free online tools designed for everyday use in India and beyond. Every tool runs entirely in your browser — your data never leaves your device, so calculators and converters are private by design.
Yes. Every tool on OpenCalculator is completely free to use, with no account, no trial period and no hidden charges.
Yes. All calculations and conversions happen locally in your browser using JavaScript. We do not upload, store or see the numbers, text or images you enter.
Yes. The entire site is responsive and every tool has been designed to work smoothly on Android and iPhone browsers.
No. OpenCalculator works directly in Chrome, Safari, Firefox, Edge or any modern browser — nothing to download or install.