Solar Battery System Sizer
Estimate battery size, solar panel quantity, and inverter size for your home, shop, or customer project.
Choose how you want to use this tool.
Do you have grid power?
Choose the option that best matches your home, shop, or business.
Solar estimate
How do you want to estimate your electricity use?
Estimate for me
Choose your home or business size. Best if you are not sure about exact kWh.
Installation location
Choose where the system will be installed. We use local sunlight data to estimate solar panel quantity.
Using local sunlight data to estimate solar panel quantity.
Advanced: edit sunlight value
Only change this if you know your local solar data or your installer provided it.
Need local sunlight data?
Advanced users can check Global Solar Atlas and estimate Peak Sun Hours from GHI.
Open Global Solar Atlas- Search your city or click your location on the map.
- Find the annual GHI value.
- Peak Sun Hours ≈ GHI ÷ 365.
GHI = 1,460 kWh/m²/year → PSH ≈ 1,460 ÷ 365 = 4.0 h/day
Choose the wattage of one solar panel. If you are not sure, keep the default.
Please enter a valid panel wattage between 300W and 800W. Current result uses the last valid panel size.
Enter total daily energy use
Use this if you know your approximate total daily energy need, or if your electricity bill is reliable because grid power is stable.
kWh/month
kWh/day
Installation location
Choose where the system will be installed. We use local sunlight data to estimate solar panel quantity.
Using local sunlight data to estimate solar panel quantity.
Advanced: edit sunlight value
Only change this if you know your local solar data or your installer provided it.
Need local sunlight data?
Advanced users can check Global Solar Atlas and estimate Peak Sun Hours from GHI.
Open Global Solar Atlas- Search your city or click your location on the map.
- Find the annual GHI value.
- Peak Sun Hours ≈ GHI ÷ 365.
GHI = 1,460 kWh/m²/year → PSH ≈ 1,460 ÷ 365 = 4.0 h/day
Choose the wattage of one solar panel. If you are not sure, keep the default.
Please enter a valid panel wattage between 300W and 800W. Current result uses the last valid panel size.
Calculate by appliances
List the appliances you use every day for a more detailed estimate.
Installation location
Choose where the system will be installed. We use local sunlight data to estimate solar panel quantity.
Using local sunlight data to estimate solar panel quantity.
Advanced: edit sunlight value
Only change this if you know your local solar data or your installer provided it.
Need local sunlight data?
Advanced users can check Global Solar Atlas and estimate Peak Sun Hours from GHI.
Open Global Solar Atlas- Search your city or click your location on the map.
- Find the annual GHI value.
- Peak Sun Hours ≈ GHI ÷ 365.
GHI = 1,460 kWh/m²/year → PSH ≈ 1,460 ÷ 365 = 4.0 h/day
Choose the wattage of one solar panel. If you are not sure, keep the default.
Please enter a valid panel wattage between 300W and 800W. Current result uses the last valid panel size.
Hours per day means how many hours this appliance is normally used each day.
| Appliance | Watts | Quantity | Hours per day | Use at the same time? |
|---|
Off-grid Solar System
Estimate a full solar system for daily use without grid power.
Choose the wattage of one solar panel. If you are not sure, keep the default.
Please enter a valid panel wattage between 300W and 800W. Current result uses the last valid panel size.
Installation location
Choose where the system will be installed. We use local sunlight data to estimate solar panel quantity.
Using local sunlight data to estimate solar panel quantity.
Advanced: edit sunlight value
Only change this if you know your local solar data or your installer provided it.
Need local sunlight data?
Advanced users can check Global Solar Atlas and estimate Peak Sun Hours from GHI.
Open Global Solar Atlas- Search your city or click your location on the map.
- Find the annual GHI value.
- Peak Sun Hours ≈ GHI ÷ 365.
GHI = 1,460 kWh/m²/year → PSH ≈ 1,460 ÷ 365 = 4.0 h/day
| Appliance | Watts | Quantity | Hours per day | Use at the same time? |
|---|