I am converting a Van into a camper and will be having a 240 volt supply as well as DC What sice circuit breaked would I require is 16 amp too high , possibly will run a hotplate, mini oven and a small heater not all at once though

Add up all of the appliances, and apply the diversity factor. Thats what its for. This will then tell you what size supply cable to use, and whit size breaker.

Bear in mind that the most power you will get on site is 16amp. Some sites only provide 10, been on some that only provide 4..

JohnW

16A is fine.
Double hotplate are usually 2kw, mini ovens about 1.5kw. That is about14A all in. Remember many appliances tae their power at 240V rather than 220, not that it makes a lot of difference.
And allow a couple of amps for the all important beer fridge.

And in France we often got offered the choice of 2, 6, 10A supplies.

May as well use a 2.5mm 3core flex and a 16A breaker. Not sure if campsite supplies tend to be on an RCD, but you certainly need one somewhere when sitting inside a metal chassis!

Yep, sites have 9or should have) an RCD for each outlet. May not happen in Europe though......
A garage type RCD unit should be ideal, one 16A and one 6A mcb. Vans tend to be wired with 3 core flexy stuff, guess it is easier to feed through awkward bits.