Vanlife Calculators
Practical, UK-specific calculators to size, spec, and plan your vanlife system.
UK-Specific Vanlife Calculators
Every calculator on this page is built around UK conditions. Solar estimates use UK peak sun hours (averaging 2.8 hours per day across the year, compared to 5-7 hours in southern Europe). Insulation calculations assume a temperate Atlantic climate, and fuel costs default to current UK pump prices. Generic online calculators built for sunnier countries will oversize your solar array and leave you short of power in a Scottish November.
Start with the Solar and Battery Calculator if you are building a new system, the Electrical Load Calculator to audit what you already have, or the Insulation Calculator before you buy any van insulation materials. All tools run entirely in your browser.
Solar & Battery Calculator
Size your leisure battery bank, solar array, inverter, and charging setup based on your actual daily appliance usage.
Fuel Cost Calculator
Estimate fuel spend for any trip. Choose your currency, unit system, and volume standard.
Van Payload Calculator
Check your van's legal payload after conversion, kit, passengers, and gear to make sure you stay road-legal.
Electrical Load & Wire Calculator
Size every circuit in your van build, covering fuse ratings, cable cross-sections (mm²), and voltage drop checks per BS 7671.
Insulation Calculator
Compare insulation materials, calculate U-values, and size your heater with zone-by-zone heat loss analysis for your van build.
Water Tank Calculator
Size your fresh water tank based on real daily usage, refill frequency, and lifestyle, with greywater planning and UK disposal guidance.
LPG Gas Bottle Calculator
Calculate how long your LPG bottle will last, track costs per day, and compare propane vs butane. Built for UK vanlife.
Condensation & Dew Point Calculator
Assess your van's condensation risk by checking dew point, wall surface temps, moisture sources, and ventilation balance with prevention advice.
Ventilation & Air Change Rate Calculator
Size your roof fan, calculate ACH, model steady-state CO₂ levels, and balance daily moisture loads for healthy van air quality.
Composite Wall U-Value Calculator
Build your van wall layer-by-layer to calculate overall U-value, heat loss, material costs, and vapour resistance using ISO 6946.
Interstitial Condensation Predictor (Glaser)
ISO 13788 Glaser method. Model temperature and vapour pressure through every wall layer to pinpoint exactly where the dew point crosses and condensation forms.
Frequently Asked Questions
Why are UK solar estimates lower than calculators designed for other countries?
The UK averages around 2.8 peak sun hours per day across the year, compared to 5-7 hours in southern Europe or the US south-west. In winter, a UK van in Scotland might see under 1 hour of usable generation. Our solar calculator uses these UK-realistic figures by default, so your system is sized for the conditions you will actually encounter, not an optimistic average.
What size inverter do I need for a van conversion?
Size your inverter to handle the surge current of the highest-draw appliance, not just its running draw. A typical 12V compressor fridge draws 45W continuously but surges to 135-180W on startup. A 1,000W pure sine wave inverter is a practical minimum for a full conversion with a small induction hob; 2,000W gives headroom for an electric kettle or hair dryer. Always use a pure sine wave model for sensitive electronics and appliances with motors.
How do I calculate van payload with a conversion fitted?
Your van's Maximum Authorised Mass (MAM) minus its kerb weight gives the legal payload. A typical Transporter T6.1 LWB has a kerb weight of around 2,030 kg and a 3,200 kg MAM, leaving roughly 1,170 kg payload. A basic conversion with insulation, cladding, bed frame, leisure battery, and kitchen unit typically weighs 150-300 kg.
What insulation thickness do I need for UK winters?
For UK winter vanlife, aim for a total wall R-value of at least R-3 (0.53 m2K/W). In a typical Sprinter or Transit, 50 mm of PIR foam board in the floor and walls is a practical baseline. Roof insulation matters most because heat rises; 75 mm there is not excessive for northern England or Scotland.
How much water should I carry for vanlife in the UK?
A typical vanlifer uses 5-15 litres per day for drinking, cooking, and minimal washing. A 40-litre tank gives 3-8 days of independence, which suits most UK vanlife where you pass service points or supermarkets regularly. If you plan extended wild camping in remote Scotland, 80-100 litres is more comfortable.