Van conversion calculators
The maths a conversion actually needs — worked from published standards and real build data. Free, no account, no email.
Wire gauge & fuse
Work out DC cable gauge and fuse size for a camper van circuit: enter amps, run length and voltage drop. ABYC ampacity plus the 3 % voltage-drop rule, in AWG and mm².
Ventilation (EN 721)
How much fixed ventilation a camper needs under EN 721: required high and low vent free area in mm² from your floor area, including the ×2 penalty for wall-mounted high vents.
Water autonomy
How many days your fresh tank lasts, and what size tank you need. Real off-grid usage figures per person, plus the grey-tank check most planners forget.
Gas locker & vent
Size a camper gas bottle locker and its drop-out vent to EN 1949: internal box dimensions from your bottles, required floor vent area, and the bottle weight for your payload.
Payload & licence
What payload your conversion must leave free: the EN 1646-2 minimum reserve, how much is left after kerb weight and build weight, and whether you stay inside a category B licence.
Bed height & garage
Find a bed platform height that clears your bikes underneath and still lets you sit up in bed. The single most-regretted dimension in van conversions, worked both ways.
Or let your layout do the typing
Every calculator here also lives inside the VanPlot editor, where it reads your real van: surface areas, cable run lengths, tank volumes and the parts you've placed. No measuring, no re-typing.
Open the 3D planner — freeWho makes this
I'm Vladimir. I'm planning my own conversion, and none of the tools I tried could tell me whether a layout would fit or what it would do to the rear axle, so I made this one. I work on it alone. If something's wrong or missing, write to me — the address goes to my inbox.
Vladimir Šterjoski