Estimate Watts, Amps, Solar Panels, Solar Chargers, Batteries and Cost for it all.

Offgrid & RV Solar System Calculator

Use this tool to estimate your Cabin or RV power needs , solar panels, solar chargers and batteries.

Note: Currently this tool is not very mobile friendly, we hope to change this soon. We always appreciate feedback.

Power Usage Estimates

Choose from preconfigured appliance and devices or add your own custom items. Each line item can be adjusted for power usage and hours used. To calculate your own power requrements for an appliance multiply amps x volts.

Why all Watts? Watts are consistent across AC or DC and Many Voltages. To convert to amps divid watts by voltage (Watts / Volts = Amps).



Watts (Volts x Amps)

Hours used per Day

Total usage per day

Total Watt Hours:


How many days of no sun or cloudy days before you need to plugin or run a generator.

How many hours of usable sunlight will the panels receive? MN Summer is about 5. Find yours using a solar calculator (new window link).

Larger Solar Panels mean less holes in roof, but harder to find the open space without racking. Smaller panels mean less visible from the ground and more able to Tetris solar across the roof of your RV.

Solar Panels Total

To recharge battery bank fully from Solar in 5 Hours

Solar Chargers Total

Victron MMPT Smart Solar 100|50

Currently assuming a 12v DC System. Larger systems will gain efficencies from 24 or 48v DC, experiment with options below. You might also reaplce 2 50 amp chargers for 1 100 amp charger on your particular system.

Batteries & DC Power System

Higher the voltage, more efficencies you gain with wiring and solar chargers. Step down converters are relatively inexpensive and can be a great way to still run 12v appliances with a 24 or 48v battery bank. Note: when adjusting DC voltage the solar chargers will adjust and batteries will be forced into multiples of 1,2 or 4 depending on voltage.

Larger batteries mean less wire and some space savings.

Batteries Total


Daily Watt Hours

1000 wh

Total Watt Hours


Total Estimated Watt Hours Required For Batteries

Estimated Component Cost

All Figures are rounded up for better performance. Example: if only 2.1 solar panels would be required, we'll recommend 3.

This is meant to serve as an estimation tool only. It does not account for installation, wire, fuses, breakers, diconnects, etc.