Electric hook-up calculator
A guide, not advice. Check your kit maker's figures before you buy or pack.
The calculator needs JavaScript. The worked example, sum and figures below show exactly how it works, so you can do it yourself. A guide, not advice.
Short answer
Enter the voltage and current limit stated by the campsite, then add the wattage ratings from your appliances. The calculator compares the total with the supply capacity and an unused-capacity margin you choose. It does not assess startup current, cables, electrical compatibility or site rules.
Worked example
| You enter | Value |
|---|---|
| Supply voltage shown by the campsite | 230 V |
| Hook-up current limit shown by the campsite | 10 A |
| Appliance power ratings from their labels | 1200, 800 W |
| Capacity to leave unused | 20% |
Entered appliance ratings are within the planning capacity.
| Result | Value |
|---|---|
| Combined appliance rating | 2000 W |
| Hook-up capacity from your figures | 2300 W (230 V × 10 A; 0.2% held back) |
| Load comparison | Entered appliance ratings are within the planning capacity. |
Show the working
- Appliance ratings: 1200 + 800 = 2000 W
- Supply capacity: 230 V × 10 A = 2300 W
- Planning capacity after 0.2% margin: 2295 W
How it works
- Combined appliance rating = sum of the wattages you enter
- Hook-up capacity = supply voltage × current limit
- Planning capacity = hook-up capacity × (1 − unused-capacity margin)
Use the rating plate for each appliance and the campsite's stated supply limit. Startup current, simultaneous operation, cable limits and site rules also matter; this is not an electrical safety assessment.
Our figures (adjustable)
These are our planning allowances and, once checked, typical figures with their sources. They aren't facts about your kit: change any of them in the calculator.
This calculator has no built-in defaults: every figure comes from you or your kit's own label.
What to buy
Shopping links will appear here once our retailer partners are confirmed. We don't rank kit by testing it: see our spec-based kit guides.
FAQs
How many watts can a campsite hook-up supply?
It depends on the supply rating for your pitch. Check the campsite listing or ask the site, then compare it with appliance label ratings.
Can I run every appliance at once if the total is below the limit?
Not necessarily. Startup loads, cables, connections and campsite rules matter. Follow appliance instructions and ask the site if you are unsure.
Guides that use it
Camping in autumn
Camping in autumn: check overnight temperatures, bag ratings, mat insulation, wet kit and shorter daylight before you pitch.
Electric hook-up explained
What electric hook-up gives you on a UK campsite, how to add up the loads before you plug in, and what to do if the supply trips.
What can you run on electric hook-up?
How to work out what you can run on campsite electric hook-up: read the appliance labels, add up the loads, and stay within the site's supply.
Camping in October half-term
Camping in October half-term: checking the forecast, sleep kit, campsite opening and arrival plans for cold autumn nights.