ASI Restroom Sign

LRV Cal­cu­la­tor for ADA Sig­nage: How to Mea­sure Col­or Contrast

Kristin Adkins

Sum­ma­ry: Learn how to cal­cu­late col­or con­trast for ADA-com­pli­ant sig­nage using Light Reflectance Val­ue (LRV). While a 70% LRV con­trast between text and back­ground is the indus­try stan­dard for opti­mal leg­i­bil­i­ty, slight vari­a­tions can still be com­pli­ant. Use the pro­vid­ed LRV math­e­mat­i­cal for­mu­la and stan­dard man­u­fac­tur­er paint swatch­es to ensure reg­u­la­to­ry accessibility.

When design­ing acces­si­ble spaces, ensur­ing your indoor and out­door direc­tion­al signs are easy to read is a best prac­tice and often a legal require­ment. Under the Amer­i­cans with Dis­abil­i­ties Act (ADA) and local build­ing codes, achiev­ing the right col­or con­trast is essen­tial for visu­al clarity.

Here is a break­down of how Light Reflectance Val­ue (LRV) works, how to use the LRV con­trast for­mu­la, and how to ensure your sig­nage meets reg­u­la­to­ry standards.

What is the 70% LRV Con­trast Rule?

As an indus­try rule of thumb, a 70% LRV con­trast between sign text and its back­ground col­or is the ide­al guide­line to fol­low when eval­u­at­ing design and fin­ish options.

  • Where to find LRV data: Most major com­mer­cial paint man­u­fac­tur­ers include LRV num­bers for their col­ors in their swatch books.
  • Our stan­dards: LRV val­ues for all paint fin­ish­es in our stan­dard ranges, along with pre-cal­cu­lat­ed con­trast break­downs, can be found in our offi­cial Stan­dard Col­or Documentation.
Jester Park ADA

Our LRV Con­trast Formula

To man­u­al­ly cal­cu­late whether your cho­sen col­or com­bi­na­tion meets ADA guide­lines, use the stan­dard math­e­mat­i­cal for­mu­la for light reflectance:

Con­trast = ( B1 — B2) x 100 / B1

B1 = LRV of the lighter area

B2 = LRV of the dark­er area

Exam­ple: If your back­ground col­or has an LRV of 80 (B1) and your text col­or has an LRV of 20 (B2), the cal­cu­la­tion is:

(80 — 20) x 100⁄80 = 75% con­trast. This com­bi­na­tion com­fort­ably pass­es the 70% benchmark.

OSF URGO 20

Is 70% a Strict Legal Requirement?

Our expe­ri­ence in archi­tec­tur­al sig­nage has shown that the 70% fig­ure is not always a mag­ic number.

Depend­ing on the spe­cif­ic hues, light­ing con­di­tions, and fin­ish tex­tures cho­sen, con­trasts a few per­cent­age points below the rec­om­mend­ed 70% thresh­old can still yield high­ly leg­i­ble, com­pli­ant results. How­ev­er, aim­ing for the 70% tar­get is the safest way to ensure your facil­i­ty’s sig­nage remains uni­ver­sal­ly acces­si­ble and com­pli­ant with region­al acces­si­bil­i­ty inspectors.

Need Help Cal­cu­lat­ing Your Sign Contrast?

Con­tact our team today to talk col­or selections.

Get more ADA inspi­ra­tion and info here.

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