# Essential Backup Load Planner

Choose outage hours for essential appliances and calculate an AC energy budget.

[Open this tool](https://whatson.pk/backup-load-calculator/)

Category: Solar & Battery

Backup planning is often about a few essential appliances during an outage, rather than the whole home's daily energy.

Enter only the loads you intend to support and their outage operating hours. Compare the energy budget before choosing storage capacity.

## Inputs and controls

* Extra energy allowance (%). Allowed range: 0 to 100
* Appliance
* Quantity (units). Allowed range: 1 to 10000
* Running power per unit (W). Allowed range: 0 to 1000000
* Daily operating time (hours). Allowed range: 0 to 24
* Duty factor (%). Allowed range: 0 to 100

## How to use

* Enter extra energy allowance.

* Add the entries in essential loads during the outage as separate rows. Include appliance, quantity, running power per unit, daily operating time and duty factor for each row.

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


## Why use this tool

A dedicated outage schedule helps keep optional daytime consumption out of the essential backup calculation.


## Before relying on the result

Hours refer to the outage, not necessarily a full day. Connected power is not an inverter surge rating.


## Tool limitations

Hours refer to the outage, not necessarily a full day. Connected power is not an inverter surge rating.

## Questions

### Are the hours a full day assumption?

Not necessarily. They refer to the outage period you enter. Use the expected running hours within that period.

### What should I check before using Essential Backup Load Planner?

Check Extra energy allowance, Appliance, Quantity and Running power per unit. 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.