Luminance Contrast Calculator

Calculate the contrast needed for accessibility in building elements like doorways and TGSIs

Luminance Contrast Calculator

Calculate the contrast needed for accessibility in building elements like doorways and TGSIs

LRV

LRV 1:

LRV 2:

Contrast:

Suitable for building elements such as doorways, stair nosings, toilet seats and TGSIs i.e. min 30% contrast.
Suitable for Discrete TGSIs i.e. min 45% contrast.
Suitable for Composite TGSIs i.e. min 60% contrast.

LRV stands for Luminance Reflectance Value
TGSI stands for Tactile Ground Surface Indicator

The contrast formula used in the app for Australia is the Bowman-Sapolinski Equation with LRV readings which are to be obtained as noted in AS1428.1-2021 is

125(Y2-Y1) / (Y1+Y2+25)
where Y2 is the LRV of the lighter area and Y1 is the LRV of the darker area.

The recommendations vary from 30% to 60% based on the element. Please refer to AS/NZ1428 suite of Australian Standards for details.

Note that LRV is on a scale of 0 to 100 (black to white), however both white and black are never absolute and therefore in reality B1/Y2 never equals 100 and B2/Y1 is always greater than 0.

Disclaimer:
Use at your own risk. The designer / Vista Access Architects shall not be held liable for use of the app.