Calibration Center
Screen Calibration for 1:1 Physical Accuracy
Screen sizes and pixel densities vary between monitors, laptops, and smartphones. Calibration matches your display's CSS pixels to real-world physical millimeters, enabling true 1:1 scale measurements.
Current Calibration Status:
Checking calibration...
Scale: 3.780 px/mm · 96.0 PPI · Method: estimated
The international bank card format (ISO/IEC 7810 ID-1) is strictly standardized at 85.60 mm wide by 53.98 mm high (3.370″ × 2.125″). Place your physical card flat on your screen and adjust the slider until the outline matches your card's physical edges.
Edge to match on card:
Target Reference Scale (85.60 mm):323.5 CSS px (3.779 px/mm · 96.0 PPI)
Fine adjustment:
The Mathematics of Physical Calibration
Unlike physical rulers made of steel or wood with static divisions, a computer monitor or phone display consists of pixels whose physical size is entirely governed by hardware manufacturing and software scaling:
• Rendered Scale: pxPerMm = renderedCardPixels ÷ physicalCardMm
• Imperial Scale: pxPerInch = pxPerMm × 25.4
• True Physical Scale: Physical 1:1 on display glass
Because operating systems apply arbitrary UI scaling (e.g. 125%, 150%, or 2x/3x Retina scaling) and web browsers do not know your monitor's physical diagonal, physical card calibration is the only scientifically reliable method to achieve 1:1 real-world size.