ToolPatch

One page. One job. Done.

← Back to all tools
Solar & Power

Solar Array Size Calculator

Calculate required PV array size and panel count.

Last validated: Pending

Use this free online Solar Array Size Calculator to estimate required PV array capacity and panel count from daily energy use, peak sun hours, system efficiency, oversize factor, and panel wattage. It is built for off-grid, RV, cabin, marine, and backup-power planning where a quick first-pass array size is needed. The output shows required DC solar capacity and approximate module count so you can compare panel options. Results depend on local irradiance, shading, seasonality, tilt, wiring losses, and battery behavior, so treat the number as a planning estimate before final system design.

Permalink

Input Pattern

Enter values in the left panel, keep units explicit, run the calculation, then copy or share the result. Invalid fields are highlighted immediately.

Site & Load Data

How much energy you use per day on average.

Average daily equivalent full sun hours for your location.

Required Array Size

Input your usage and sun data

We'll calculate the panels you need.

How to use this tool

  1. Enter daily energy consumption, peak sun hours, system efficiency, oversize factor, and panel wattage.
  2. Use conservative peak-sun-hour and efficiency assumptions if the site has shading, winter operation, or long cable runs.
  3. Run the calculator and review required array size and estimated panel count.
  4. Compare the estimate with site-specific solar data and installer guidance before purchasing equipment.

Worked Example

Auto-generated from the tool's current default or entered inputs.

Example Inputs

Expected Outputs

Interpretation

Explore more versions

Tailored guides for specific audiences, regions, and scenarios.

core

Solar Array Size Calculator

 geo

Solar Array Size Calculator for Germany

 geo

Solar Array Size Calculator for United Kingdom

 geo

Solar Array Size Calculator for United States

 persona

Solar Array Size Calculator for Homeowners

 persona

Solar Array Size Calculator for Small Business

Solar Panels and PV Equipment

Shop for high-efficiency monocrystalline and bifacial solar panels.

Sponsored