Tell us what you want to power and where you are. We calculate the battery, inverter and solar panel size you need and show the kits in stock that match.
This solar kit calculator sizes a complete off-grid or backup system from what you actually want to run. Pick your appliances and how many hours a day you use them, or enter your monthly electric bill. Add your ZIP code and the calculator pulls NASA solar data for your location, so the panel size reflects the real peak sun hours where you live - including the darkest month of the year.
You get three numbers: the battery capacity you need (Wh), the inverter output that covers your loads (W), and the solar array that recharges the battery every day (W). Then it matches those numbers against the solar kits, solar generators and portable power stations we have in stock, and shows the best-value kit, a budget option and one with more headroom.
Every system is sized the same way. The solar system size calculator on this page does the math for you:
For example, a cabin using 5 kWh a day in a location with 4.5 peak sun hours needs roughly a 6.8 kWh battery for one day of autonomy and about 1,500 W of solar panels.
Use it as an off grid solar calculator for cabins and tiny homes, an RV solar calculator for vans and campers, or a battery backup calculator for keeping the fridge, well pump and internet on during outages. For smaller loads it also works as a solar generator and portable power station calculator - it will tell you when a power station alone is enough and how many watts of panels to add.
Divide your daily energy use (Wh) by your peak sun hours, then by 0.75 for real-world losses. 5,000 Wh a day at 4.5 sun hours needs about 1,480 W of panels - four 400 W panels. The calculator uses your ZIP code to get the sun hours.
Multiply daily use by the number of days you want to run without sun, then divide by 0.8 and 0.92. One day at 5 kWh needs about 6.8 kWh of LiFePO4 storage; two days need about 13.6 kWh.
Yes. Choose the camping, RV or emergency preset and it will recommend power stations when their output and capacity cover your loads, and flag when you need extra panels or an expansion battery.
It is a planning estimate based on typical appliance wattages and long-term NASA solar averages. Check the nameplate watts of your own appliances for a closer result. Grid-tied and whole-home installs should always be reviewed by a licensed electrician.
