All 15 solar calculators
Each tool solves one sizing decision and hands you the input for the next. All free, all showing their working, none requiring an account.
Solar Wire Tools
Solar Wire ToolsAbout this category
- Solar Wire Size CalculatorFind the right wire gauge for any DC circuit in a solar system.
- 12V Solar Wire Size CalculatorWire sizing for 12 volt solar, RV, van and marine circuits.
- 24V Solar Wire Size CalculatorWire sizing for 24 volt off-grid and cabin systems.
- 48V Solar Wire Size CalculatorWire sizing for 48 volt off-grid and whole-home systems.
- RV Solar Wire Size CalculatorWire sizing for RV, camper van and trailer solar builds.
- Battery to Inverter Wire Size CalculatorSize the highest-current cable in the whole system.
- Solar Panel to Charge Controller Wire Size CalculatorSize the run from the array to the controller, per NEC 690.8.
Solar Electrical Tools
Battery Tools
System Sizing Tools
System Sizing ToolsAbout this category
- Solar Inverter Sizing CalculatorSize an inverter from continuous load and motor surge.
- MPPT Charge Controller Sizing CalculatorMatch a controller to your array, including cold-weather Voc.
- Solar Panel Series & Parallel CalculatorWork out string voltage and current for any wiring layout.
- Solar Array Size CalculatorHow much array your daily energy use actually needs.
What is not here yet
Conduit fill, AC voltage drop, grounding conductor sizing and IEC-based metric ampacity are all absent on purpose. Each needs data or a model we can source properly first, and the methodology page states exactly what these tools do and do not cover. We would rather have a gap than a guess.