PROFESSIONAL SOLAR SIZING TOOL

Design your perfect
solar system.

Get a complete, engineering-grade system estimate in minutes. Size your panels, batteries, inverter, and charge controller—all in one place.

Start calculating →▶ How it works

10,000+Systems sized99.5%Calculation accuracyFreeNo signup required

SYSTEM DESIGN WORKSPACE

Build your solar system

Adjust your requirements and get an engineering-grade estimate instantly.

Live calculation

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Solar panel calculator

Size your array based on daily energy needs and local sunlight.

Daily power consumptionCheck your utility bill for average daily usePeak sun hours / dayhoursTypical range: 3–7 hoursSystem efficiency%Includes wiring and conversion lossesPreferred panel sizeHigh-efficiency monocrystalline recommended

Required array output4.22 kW

Solar panels needed10 panels

Installed capacity4.5 kWp

WHY HELIOS

Confidence in every calculation.

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Instant results

Every input updates your system design immediately—no waiting or page reloads.

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Engineering formulas

Industry-standard safety factors, efficiency losses, and sizing methodology.

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Built for sustainability

Understand both the financial and environmental impact of your solar system.