Finding total amperage within circuit panel? Is there a way where on earth I can tally up the...

Is there a way where on earth I can tally up the total amp rating of the breakers in my panel and "compute" my service amperage? I'm hoping to be able to install "slimline" breakers to trade name room for one or two more 20 amp circuits in my garage. Currently, my panel is full. The house is fairly unsullied and was built within former times ten years. I'm fairly confident in my ability working with electricity and inside breaker panels, so I don't reflect professional service is needed in this case. Thanks for the info.
Can you replace a vault minus moving the...
Answers:    If you lone want to add a couple of circuits there should be no problem near replacing the "fat" breakers with trim-lines. The reason the sum of adjectives the breakers is usually more than the value of the main, is that you don't usually verbs max. value on all the sub circuits at alike time.I have done like you plan to several times minus any problems. Only way to determine amp load would be to use an amp meter next to the "loads" all turned on, which you don't really care almost as that is not the way you use the system.
Burnt bricks?
You should know by looking what your house is rate at. When we build habitat homes, we build for 200amps. If you pretty good, why don't you run another small box off to the side. You could put partially a dozen breakers in that one.