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Add Your Appliances
Select your appliances and enter how many you use at the same time.
FREE SOLAR TOOL
Find the Right Inverter and Battery Size
Choosing the correct inverter and battery can be confusing. The FITIWEBS Solar & Inverter Calculator helps you estimate the equipment capacity required based on your appliances and desired backup time.
Enter your appliances below and get an estimated inverter size, battery capacity, solar panel requirement and recommended system voltage.
SIMPLE PROCESS
How the Solar Calculator Works
02
Set Backup Time
Tell the calculator how many hours you want your battery system to run.
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Get Your System Estimate
Receive an estimated inverter, battery, solar panel and system voltage recommendation.
FITIWEBS CALCULATOR
Calculate Your Solar System Size
Enter the appliances you want to power.
Your Appliances
| Appliance | Watts | Quantity | Running Watts | Remove |
|---|
SOLAR EDUCATION
How to Choose the Right Inverter Size for Your Home
The correct inverter size depends on the total electrical load you want to run at the same time. Appliances such as refrigerators, freezers, pumps and air conditioners can require additional starting power.
For this reason, simply adding appliance wattages is not always enough. A suitable safety margin should be included when selecting an inverter.
How to Calculate Battery Capacity
Battery capacity depends on your power consumption, required backup duration, battery voltage, battery chemistry and usable battery capacity.
A simplified calculation is:
Battery Energy = Load × Backup Time
The result can then be adjusted for battery efficiency, inverter losses and usable depth of discharge.
How Many Solar Panels Do I Need?
Solar panel sizing depends on your daily energy requirement and the amount of useful sunlight available. Panel wattage, system losses and solar conditions should also be considered.
The FITIWEBS calculator provides an initial estimate. A professional solar system design should verify the final panel configuration and MPPT voltage range.
FAQ
Frequently Asked Questions
How do I calculate the inverter size I need?
Add the running watts of the appliances you want to operate at the same time and allow additional capacity for starting or surge loads. The required inverter size also depends on power factor and appliance characteristics.
How many batteries do I need for my inverter?
Battery requirements depend on your total load, desired backup time, battery voltage, battery chemistry and usable depth of discharge.
How many solar panels do I need for my home?
Solar panel requirements depend on your daily energy consumption, panel wattage, available sunlight and system losses.
What battery is best for a solar inverter?
Lithium iron phosphate batteries are commonly preferred for many modern solar systems because they can provide high usable capacity and long cycle life. However, the battery should always be compatible with the selected inverter.
Can this calculator replace a professional solar design?
No. This tool provides an initial estimate. A professional installation should verify equipment specifications, MPPT limits, battery requirements, cable sizing, protection devices and site conditions.
Need a Professional Solar Installation?
Get professional solar system design, inverter sizing and installation from FITIWEBS.
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