Thanks for the link. I used the calculator. It's a bit difficult to find the right exercise type. Have you been to Gymophobics? It is a 30 resisted tension 'circuit' - 8 machines and two floor exercises. You do 3 mins at each station. You essentially pump air into the machine which creates the equivalent of KGs to exercise different parts of your body. On the back exercise I do 20kg, on the triceps I do some reps on 8kgs and some on 4kgs etc.
I wasn't sure what to go for so I went for 'light weightlifting' and it suggested 172 calories for 30 mins.