In an hour of soaking in a hot tub you burn on average of 100 to 130 calories per hour of soaking in the hot tub.
Soaking in a hot tub does burn some calories and is a nice relaxing way to ease sore muscles as well but you won't burn off a lot of calories when soaking in a hot tub.
So if you're trying to lose weight soaking in a hot tub for 30 minutes to an hour each time can help burn off some calories but you should also exercise and what what you eat.
Exercising, changing your diet and soaking in a hot tub daily can help you shed over 100 lbs of weight in a year and sometimes more.
I did lose a few lbs over a few months of sitting in a hot tub but exercising and changing my diet really helped to get rid of the weight and fat.
Exercise is also healthy for you too as you strengthen your heart and prevent heart disease, strokes and lower your blood pressure as well.