YouFit Express Circuit - Number of Calories Burned?

Hello,
I'm currently a member of the gym YouFit and occasionally do their Express Circuit, which alternates between strength training (on machines) and cardio (I do jumping jacks, aerobic step, etc).

The Express Circuit lasts about 30 minutes and you do about a minute of strength training, then about a minute of cardio, then back to the strength training and so on.

I haven't been able to get a good estimate from YouFit's staff re: how many calories the Express Circuit burns. I'd like to get at least an estimate so I can know if the Express Circuit's actually worth my time.

If anyone can help me estimate, that'd be great. I'm a 34-year-old woman currently hovering at around 170 lbs.

Thanks!