Free van & RV electrical design tool
Get a complete electrical design. Not just a battery number.
Tell us what you want to power. Roam Wired turns your appliances and travel style into a calculated system with a wiring diagram, correctly sized components, cable and fuse schedules, and a parts list.
Your finished output
One plan you can actually build from
Interactive wiring diagram
See how every major component and connection fits together.
Battery and charging sizes
Size the battery bank, solar, DC-DC charging and inverter from your loads.
Cable and fuse schedule
Get calculated cable sizes and protective fuse ratings for each circuit.
Complete parts list
Turn the design into a practical shopping list with compatible components.
Live safety checks
Catch undersized cables, missing protection and design conflicts while you edit.
Downloadable design report
Keep the diagram, calculations and schedules together for your build.
Start your electrical design
Choose the route that suits you.
Answer plain-English questions for the quickest result, start from a proven electrical template, or open a blank canvas if you already know what you need.
What you get for free
Every important electrical decision in one design.
Instead of collecting disconnected calculator results, you get a system where the loads, components, cables, fuses and costs update together.
Interactive wiring diagram
See how every major component and connection fits together.
Battery and charging sizes
Size the battery bank, solar, DC-DC charging and inverter from your loads.
Cable and fuse schedule
Get calculated cable sizes and protective fuse ratings for each circuit.
Complete parts list
Turn the design into a practical shopping list with compatible components.
Live safety checks
Catch undersized cables, missing protection and design conflicts while you edit.
Downloadable design report
Keep the diagram, calculations and schedules together for your build.
How it works
From appliance list to buildable electrical plan.
Tell us what you will power
Choose your fridge, lights, laptops, cooking equipment and other loads, then add how long you use each one.
We calculate the complete system
The tool sizes storage, charging, solar, inverter, cables and protection using US-localised assumptions.
Review, edit and export
Fine-tune the live diagram, swap parts and download the information you need to plan the installation.
Designed to help you plan—not to hide the calculations.
See the assumptions, review all 42 checks and have mains-voltage work verified by a qualified professional.
What does the electrical design tool do?
Roam Wired is a free off-grid power calculator for US van life, RVs and overlanding. You enter the appliances you plan to run — a 12V fridge, CPAP, laptop, lights, a water pump — and it adds up your real daily energy use in watt-hours, then sizes the battery, solar and inverter to match.
Whether you're building a dual-battery system into a van or choosing a portable power station, the numbers are the same: figure out your daily watt-hours first, then buy to fit. Once you know your target capacity, our US power station guides help you pick the right unit.