Screen & Physical Ruler
Use a CSS pixel ruler and calibrate against a known physical reference.
Calibrate with a credit card
Place a standard 85.60 mm credit card against the guide, then adjust its width until both edges match.
Estimated CSS scale — calibration required for physical measurements
About this tool
Use a CSS pixel ruler and calibrate it against a known physical reference. Free, private and browser-based. Screen & Physical Ruler runs in the browser on DevTools. There is no signup, and your input stays on this device unless the tool explicitly performs a live network lookup.
What this tool does not do
- Screen & Physical Ruler is a free in-browser utility, not a hosted API. It does not keep server-side history and is not a substitute for production verification in your own stack.
How do I use this tool?
How do I use Screen & Physical Ruler?
Open Screen & Physical Ruler, enter or paste your input, and copy the result. The page works without an account.
Related guides
Related tools
Digital Bubble Level
Measure surface tilt with a visual bullseye and a ±0.2° level threshold.
Digital Compass
Read a device heading with a manual desktop simulator and magnetic interference guidance.
Flashlight & Signal Beacon
Use a supported phone LED or a dimmable full-screen light with blink patterns, SOS and Morse signals.
GPS Speedometer
Track speed and distance from GPS with a Haversine fallback when speed is null.
I2C & SPI Bus Timing Diagram
Scan I2C device lists for address conflicts (7-bit/8-bit normalized) and inspect SPI CPOL/CPHA timing modes with pull-up and max-speed guidance. Runs entirely in your browser.
IoT Pil Ömrü Tahminleyici
Mikrodenetleyici pil ömrünü ve uyku çevrimini hesaplayın