Our Mission
To Scale Ruler was created to provide a free, accurate, and easy-to-use on-screen measurement tool that works reliably across all devices. We believe that everyone should have access to precise measurement tools without needing to purchase expensive software or physical tools.
Why Calibration Matters
Unlike many on-screen rulers that guess your screen's DPI or resolution, To Scale Ruler requires mandatory calibration using standardized physical objects. This ensures that measurements are as accurate as possible given your specific screen configuration.
Our calibration system uses universally recognized standards:
- Credit/Debit Cards: ISO 7810 standard (85.60mm × 53.98mm)
- US Quarter: 24.26mm diameter
- Printable Sheets: A4 (210mm × 297mm) or US Letter (215.9mm × 279.4mm)
Features
Multiple Units
Measure in Metric (cm) with millimeter precision or Imperial (In) with easy unit switching.
Flexible Orientation
Use horizontal or vertical ruler modes to measure in any direction.
Full Screen Mode
Maximize your measurement workspace with distraction-free full-screen mode.
Dark Mode
Comfortable viewing in both light and dark themes for any work environment.
Mobile Optimized
Fully responsive design that works seamlessly on desktop, tablet, and mobile devices.
Privacy First
All calibration data is stored locally. No measurements or personal data are transmitted.
Privacy & Data
We are committed to your privacy. To Scale Ruler does not collect, store, or transmit any personal information or measurements. All calibration data is stored exclusively in your browser's localStorage on your device. You have full control over your data and can clear it at any time.
We use Google AdSense to display advertisements, which may use cookies as disclosed in our Privacy Policy. Ads are carefully placed to never interfere with measurements or the calibration process.
Accuracy & Limitations
While we strive for accuracy, on-screen measurements have inherent limitations due to screen resolution, calibration precision, browser zoom, and viewing conditions. To Scale Ruler is intended for approximate measurements and general reference purposes only. It should not be used for applications requiring certified precision measurements.
Open Source & Standards
To Scale Ruler is built using modern web standards including Next.js, React, TypeScript, and Tailwind CSS. Our calibration system adheres to ISO and US standards for reference dimensions. We are committed to providing a transparent, standards-based measurement tool.
Contact Us
Have questions, suggestions, or feedback? We'd love to hear from you. Please visit our contact page to get in touch.