How much electricity will my item use?

The quick answer is KW's or watt multiplied by the cost per hour

Let's break it down a little:

According to THIS WEBSITE HERE - the average cost per KW (1000 watts) is about £0.15p per hour

So, if a steam shower, for example, is 2.8KW's, to run it on full power for 1 hour the most it could ever cost you would be £0.42p

2.8 x 0.15 = £0.42 per hour

One thing to note that in the case of a steam shower, they do not run constantly, only producing steam to 'top-up' the temperature and keep it constant. So the actual cost is less than the above. (The above being the most severe possible if the shower doors where left open for example)

Now let's look at some other example items:

The Vidalux 2 Person Full Spectrum Infrared Sauna is rated at 2300w (2.3kw) so given a running cost of the maximum setting of £0.35p per hour (2.3 x 0.15)

The Vidalux 4 person is 2800w and has a maximum running cost of £0.42 per hour

You can apply the same calculation to any unit if you simply multiply to KW or Watts by the average cost per KW per hour