Unified Glare Rating explained

Written by

Cliff Green

Posted on

June 19, 2018

What is UGR?

UGR stands for Unified Glare Rating and is a numerical measure of how much glare is emitted by luminaires. Glare can adversely affect wellbeing and productivity in the workplace, particularly where there are lots of computer monitors.

The UGR rating ranges from 5 to 40, with lower numbers indicating less glare. It is calculated using a strict formula where the luminescence of a lamp is divided by the visible light luminance from the room background.