Solar Panel Power Density Calculator
From rated power and module dimensions, compute power density in W/m², module efficiency and panels needed per kilowatt.
- Computes power density in watts per square metre from a panel's rated power and dimensions.
- Also returns module efficiency and how many panels are needed per kilowatt.
- Useful for comparing how much power different modules pack into the same area.
Power density
225W/m²
Module efficiency
22.5%
Panel area
1.95m²
Panels per kW
2.3
Power density is rated power spread over the panel's physical area: density = power ÷ (length × width), in watts per square metre.
- Module efficiency is that density measured against standard test conditions:
efficiency = density ÷ 1000 W/m² × 100. STC assumes 1000 W/m² of irradiance. - Panels per kW is simply
1000 ÷ rated watts— handy for sizing.
Estimates only — for guidance, not a quote or engineering specification. Nothing you enter is stored or sent anywhere; the maths runs entirely in your browser.
Frequently asked
- Is this calculator free to use?
- Yes. The power density calculator is free and needs no sign-up. It runs entirely in your browser.
- Is my data stored or sent anywhere?
- No. The calculator runs in your browser and stores nothing. The figures you enter are not saved or sent anywhere.
- What do I need to calculate power density?
- You need a module's rated power and its dimensions. From those the tool estimates power density, module efficiency and panels per kilowatt.
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