Our Mission
We believe useful tools should be freely available to everyone on the web. Calivon exists to give students, designers, engineers, and everyday users a reliable way to measure objects in centimeters, millimeters, and inches directly in their browser — no app store, no plugin, no signup required.
What We Built
Calivon is a precision measurement tool that runs entirely in your browser. Because every screen has a different pixel density, we built a calibration system that corrects for your specific display — using automatic detection, your screen's diagonal size, or a standard credit card as a physical reference.
- Online ruler in CM and MM — millimeter-level precision with clear centimeter labels
- Online ruler in inches — down to 1/16th-inch divisions
- Edge ruler — a persistent side ruler for measuring anything on your screen
- Embed generator — copy a one-line iframe to add the ruler to any website
- Dark mode — automatic and manual light/dark theme support
Privacy First
We do not collect personal data, require an account, or run advertising trackers. Your calibration settings, preferred unit, and theme are saved only in your browser's localStorage — they never leave your device. For full details, see our Privacy Policy.
Who Uses Calivon?
- Students measuring for assignments and projects
- Graphic designers checking element sizes on screen
- Engineers and makers verifying component dimensions
- Tailors and crafters estimating fabric and paper sizes
- Anyone who needs a quick measurement without a physical ruler nearby
Contact Us
Have a question, suggestion, or found a bug? Visit our Contact page to get in touch.