About the Lighting Power Density Calculator
Lighting power density in W/m² and how it compares to typical energy-code limits.
Also known as: lpd calculator, watts per square meter lighting, lighting energy density, lighting compliance.
How to use this calculator
- Enter total lighting power, floor area, space type, hours per year and the other fields.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
LPD = total lighting watts ÷ floor area
Worked example
Using the values pre-filled in the calculator above:
- Total lighting power = 300 W
- Floor area = 50 m²
- Space type: Office (8 W/m² limit)
- Hours per year = 2,500
- Electricity rate per kWh = 0.25
the calculator returns:
- Lighting power density: 6 W/m²
- Typical limit for this space: 8 W/m²
- Compliance: Within the typical limit
- Annual energy: 750 kWh