Personally I'd suggest always working to a 10amp (2300watt) maximum when looking to buy things which work together. Reason for this being that most of the campsites I've visited have had 10amp supplies and very few have had 16amp ones.
If you aim for 10amps you know you are likely to be ok and can use more on a 16amp site but if you aim at 16amps you could end up tripping the electricity.
Also - some sites only have 6amp (1300watts) so personally I would never buy any single device which uses more than say 1000watts (1kW) to be on the safe side. I'm in a tent though.
I bought a proper low wattage camping kettle which is 800watts. It is slower than a normal kettle but still fine. You could of course use a standard kettle on your gas hob if you preferred.
I bought a normal 2 slice toaster for £5 from Tesco. It is 800w and great. Camping toasters are so slow the toast dries out before it is ready. Don't buy a 4 slice though, it will likely trip the electrics
I also bought a normal filter coffee machine from Tesco. It is also 800watts and great. Obviously I wouldnt use any of the toaster/kettle/coffee machine at the same time.
My camping heater is a 400w/800w halogen which is great but again I turn it off before using any of the above appliances
Fridge always stays on along with power to charge phones/tablets etc. We cook on gas so no problems there. Radio is often on too but that is only a few watts.
3 sites I stayed at last year mentioned when arriving that if we trip the electric it also trips several other pitches (on 1 site it was the whole site) and warned that if this happened regularly those responsible would be asked to leave. Although harsh, that's fair warning. We take quite a bit of electrical equipment but are always careful about what works with what and of not over-using. Touch wood we've never tripped it out yet.
We used a travel kettle, probably the same one as Bernie47.
0.8 litres
1 kw
cordless
It needs to be descaled from time to time but use lemon juice, not vinegar.
In our trailer we used to use a normal 2KW kettle and a 2KW fan heater. We found out the hardware not to use both together.
When we bought the caravan we ditched them both and bought a 900W kettle instead. It does take about 9 minutes to boil, but we haven't noticed the waiting around for a cuppa. I'm guessing its because we're on holiday and theres bio rush.
The science may be exact but it depends on the voltage which,unless you measure it, will affect the result.
An approximation is all that is required.
saxo1