# Solar Array Size Calculator

Estimate DC capacity from a daily AC energy target and entered sun hours.

[Open this tool](https://whatson.pk/solar-size-calculator/)

Category: Solar & Battery

A daily energy target can provide a first estimate of solar DC capacity when the assumed sun hours and losses are explicit.

Enter the AC energy target and a suitable yield factor. Compare alternatives rather than treating the first capacity figure as a finished system design.

## Inputs and controls

* Daily AC energy needed (kWh). Allowed range: 0.001 to 10000000
* Capacity allowance (%). Allowed range: 0 to 100
* Peak sun hours (hours/day). Allowed range: 0.01 to 24. Enter a site and season estimate, not daylight duration.
* Overall AC yield factor (%). Allowed range: 0.01 to 100

## How to use

* Enter daily AC energy needed and capacity allowance.

* Enter peak sun hours and overall AC yield factor.

* Select Calculate result. Read the returned values alongside the assumptions below before copying, exporting or acting on the result.


## Why use this tool

The editable assumptions show why the same daily demand can lead to different array sizes.


## Before relying on the result

Yield factor includes the losses you intend to model. This is a simple energy balance, not an hourly weather simulation or outage guarantee.


## Tool limitations

Yield factor includes the losses you intend to model. This is a simple energy balance, not an hourly weather simulation or outage guarantee.

## Questions

### Does this guarantee output during outages?

No. It is a simple energy balance. Weather, hourly use, storage and equipment operation need a detailed design.

### What should I check before using Solar Array Size Calculator?

Check Daily AC energy needed, Capacity allowance, Peak sun hours and Overall AC yield factor. Use the exact units shown beside the controls and replace any example values with your own inputs.

Source page last modified (UTC): 2026-10-01T18:56:35+00:00

This profile describes the tool. It does not execute it or supply a professional certification.