Built by Van Builders, for Van Builders
OffGridVanCalc.com exists because sizing an electrical system for a self-build campervan shouldn’t mean guessing, overpaying, or trusting a one-size-fits-all rule of thumb.
Why We Built This Calculator
Every van conversion is different. A weekend camper running a fridge and a few LED lights has completely different power needs to a full-time remote-work rig running a laptop, induction hob, and heater. Most “off-grid electrical calculators” online give you a single generic number regardless of what you actually plan to run — which either leaves you under-powered on the road, or paying for far more battery and solar than you need.
We built OffGridVanCalc.com to fix that. Instead of a flat estimate, you enter your own appliances, wattages, and daily runtime, and the calculator works out your battery bank, solar array, and inverter size using the same formulas professional installers use — adjusted for your region’s sunlight, your battery chemistry, and how many cloudy days you want to plan for.
What Makes Our Numbers Different
Real Calculations, Not Guesswork
Every result is calculated live from your actual inputs — no hardcoded numbers, no generic “one size fits all” output.
AC vs DC Aware
We size your inverter only for the appliances that actually need it, so you’re not paying for capacity you’ll never use.
Region-Specific Solar Data
UK and US/Canada sunlight hours are genuinely different — our solar sizing reflects that instead of a US-only average.
Who This Site Is For
Whether you’re converting a VW Transporter for weekend trips, fitting out a Sprinter for full-time van life, or just trying to understand how much solar you actually need before buying anything — OffGridVanCalc.com is built to give you a clear, honest starting point before you spend a single pound or dollar on parts.
Ready to Size Your System?
It takes about 60 seconds — no signup, no email required.
Open the Free Calculator →