WCAG 2.1 Contrast & Luminance Calculator
Verify text legibility and color compliance against W3C Level AA and AAA standards with real-time photometric luminance scoring.
Standard 16px body copy: Optical wave mechanics and photon energy quantization.
WCAG 2.1 Compliance Matrix
Luminance: FG 0.009 / BG 0.972The Photometric Science of Visual Contrast
Visual accessibility is grounded in human neurobiology. When reading on electronic displays, the eye detects character boundaries through luminance differences between adjacent retinal receptive fields rather than color hue alone.
Photopic Luminance Equation
Relative luminance L measures physical radiant power weighted by the human spectral sensitivity curve V(λ):
Weber-Fechner Contrast Ratio
The constant +0.05 offset accounts for ambient flare light in typical viewing environments:
Datacolor SpyderX Pro
Calibrare monitor rapida cu lens-based color engine
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