Lighting Power Density
Use the Lighting Power Density. Enter Lighting watts and Floor area (ft²) for a clear result, formula explanation, and practical planning checks.
Lighting Power Density measurements
Enter your values, then calculate.
Result
How to calculate lighting power density
Lighting power density (LPD) measures lighting wattage per square foot of floor area — a standard metric used in energy codes to evaluate lighting efficiency.
How the calculation works
LPD = Lighting watts ÷ Floor area (sq ft).
Example
2,400 watts of lighting over 1,200 sq ft: LPD = 2,400 ÷ 1,200 = 2.0 W/sq ft.
Frequently asked questions
How is Result calculated?
Result = [Lighting watts] ÷ [Floor area].
Is the Lighting Power Density free to use?
Yes — every calculator on Simple Calculator Tools is free, runs in your browser, and does not require an account.
Lighting Power Density
LPD = Lighting watts ÷ Floor area (sq ft).
Let's understand your lighting power density result.
Calculate a result above and this guide will help you interpret it using this calculator's own formula and explanation.
Pro Tips for Lighting Power Density
- Energy codes (like ASHRAE 90.1) specify maximum allowed LPD by building/space type — check your applicable code's specific limit.
- LED lighting retrofits typically reduce LPD significantly compared to older incandescent or fluorescent lighting, often helping projects meet code requirements.
Common Lighting Power Density Mistakes to Avoid
- Not checking LPD against applicable energy code maximums during design, which can create a compliance issue discovered late in a project.
When to Use This Calculator
Lighting power density (LPD) measures lighting wattage per square foot of floor area — a standard metric used in energy codes to evaluate lighting efficiency.