Free browser tools
Small, focused calculators that run entirely in your browser. Nothing you type is uploaded, there is no sign-up, and there is nothing to install.
Display & Screen
Work out how sharp a screen is, how far away to sit, and what a refresh rate means in milliseconds.
- PPI Calculator — pixel density and pixel pitch from resolution and diagonal size.
- Screen Size Converter — turn a diagonal measurement into actual width and height.
- Viewing Distance Calculator — how far to sit from a TV or monitor for a sharp image.
- Refresh Rate Converter — convert Hz to frame time in milliseconds.
How this works
Every tool on this site is a single page of HTML, CSS and JavaScript. When you enter a number, the calculation happens in your own browser — the value is never sent anywhere. That is why the tools keep working offline once the page has loaded, and why there is no account to create.
Toolssok started as a Korean-language collection of everyday calculators and is now being extended into English, beginning with display and screen tools. The Korean site has around 80 tools covering pay, tax, dates, health and more.