About Sum Calculator

Why We Built Sum Calculator

We launched Sum Calculator in 2024 for a simple reason: most “online calculators” were either overloaded with ads or secretly uploading every keystroke. We wanted a tool that totals numbers instantly, never leaves the browser, and stays free—no popup banners, no data grab.

Our Mission

To provide the fastest, most private, and most accurate Sum Calculator on the web—nothing more, nothing less.

What Sets Sum Calculator Apart

Instant results:

Totals appear in milliseconds, even on 3G.

Privacy by design:

All math runs in your browser; we never send or store your numbers.

Single-purpose focus:

No currency converters, no BMI charts—just a rock-solid Sum Calculator.

Open source:

Built with Next.js 14 & TypeScript and released under the MIT licence on GitHub.

How It Works

When you press Calculate, a tiny script splits your input on commas, spaces, or line breaks, converts each token to a number, and streams the addition in JavaScript's native 64-bit precision. Nothing touches a database or server.

Who Uses Sum Calculator

Students finishing homework, teachers creating class examples, accountants balancing ledgers, data analysts cleaning CSV files—anyone who needs a trustworthy Sum Calculator that won't slow them down.

Get In Touch

Spotted a bug or have an idea?

Email us → hello@sumcalculator.org

© 2025 Sum Calculator — The fast, private way to add numbers online.