Lighting Engineering

Unified Glare Rating (UGR) Calculator for Luminaire Layouts Calculator

Unified Glare Rating (UGR) Calculator for Luminaire Layouts engineering calculator.

Quick Answer

Calculate Unified Glare Rating (UGR) Calculator for Luminaire Layouts

Calculator

Unified Glare Rating (dimensionless)
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Result Interpretation

Unified Glare Rating (UGR) Calculator for Luminaire Layouts Calculator computes Unified Glare Rating in dimensionless using the defined engineering formula and the input values provided.

Worked Example

Verified calculation

Given:

  • Background luminance = 10
  • Reference background luminance = 1
  • Sum of (L_i / L_b)^2 × ω_i over all luminaires = 100

Expected Result:

  • Unified Glare Rating = 17.5

Engineering Interpretation:

Under the given input conditions, the calculated result is: Unified Glare Rating = 17.5 dimensionless.

The actual numerical result is computed by the Runtime engine using the persisted tool definition. The values shown here come from automatically validated test cases.

Formula / Method

unified glare rating = 10 * (log(L_i / background luminance) / log(10)) - 2.5

Formula family: formula_lighting_luminaire_glare_index_evaluator_ugr_calculator

Variables

SymbolLabelRoleDescription
sum_Li_Lb_i_ratio_times_solid_angle Sum of (L_i / L_b)^2 × ω_i over all luminaires INPUT Sum of (L_i / L_b)^2 × ω_i over all luminaires
L_b Background luminance INPUT Background luminance
Lb_ref Reference background luminance INPUT Reference background luminance
ugr_value Unified Glare Rating OUTPUT Unified Glare Rating
CIE_UGR_offset CIE_UGR_offset CONSTANT CIE_UGR_offset = -2.5 dimensionless

Calculation Steps

  1. Enter the sum of (l_i / l_b)^2 × ω_i over all luminaires in dimensionless.
  2. Enter the background luminance in cd/m².
  3. Enter the reference background luminance in cd/m².
  4. Step 1: Compute unified glare rating.
  5. Read the unified glare rating (dimensionless) from the results.

Engineering Summary

Calculate Unified Glare Rating (UGR) Calculator for Luminaire Layouts

Frequently Asked Questions

What does this calculator calculate?

The Unified Glare Rating (UGR) Calculator for Luminaire Layouts Calculator estimates Unified Glare Rating based on the input parameters you provide

Why is sum of (l_i / l_b)^2 × ω_i over all luminaires important in this calculation?

sum of (l_i / l_b)^2 × ω_i over all luminaires is directly proportional to unified glare rating. When you enter sum of (l_i / l_b)^2 × ω_i over all luminaires in dimensionless, the calculator uses it in the engineering formula to compute the output

How should I interpret the result unified glare rating?

The calculator outputs unified glare rating in dimensionless. The result is computed directly from the input values using the defined engineering formula

What units should I use for the inputs?

Enter each value in the units shown next to the input field: Sum of (L_i / L_b)^2 × ω_i over all luminaires (dimensionless), Background luminance (cd/m²), Reference background luminance (cd/m²). Make sure all inputs use the specified units for consistent results

What assumptions does this calculator use?

This calculator uses automatically validated engineering formulas. Results are approximate and should be validated against site-specific conditions, applicable codes, and professional engineering judgment

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