Solar calculator
Solar System Size Calculator
Use this calculator to estimate a starting solar system size from monthly electricity use, local sunlight, panel rating and site losses.
Interactive tool
Solar system size calculator
Estimate a starting system size from monthly electricity use, local sun, panel rating and site losses. A final design still needs a site survey.
Starter estimate
- Recommended system size
- 6.3 kW
- Panel count
- 12 panels
- Approximate roof area
- 28 sq m
- Estimated monthly generation
- 630 kWh
- Likely daytime value
- 347 kWh
550 W each
297 sq ft before access gaps
70% of current use target
284 kWh may need export, batteries or load shifting
Assumes a performance ratio of 74%. Compare options using actual roof measurements, utility rules, equipment models, shading and local professional pricing.
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