Hi! They vary enormously, so make sure you read the labels. Most have the carbs by "half can" which helps as I share a can with my wife. Chicken or mushroom always seem ok (according to how low carb you go) at about 9 or 10 grams per half can. Packet soups always seem very high allowing for the fact the packet is for one person. I had a "Dim Sum" (or something like that) soup in a can from blue dragon I think which was really low at about 2 grams for half a can, but it didn't taste of anything so that explains that! Most veggie soups are high in carbs. I aim for about 10 grams for a half can, and good old Heinz Chicken and Mushroom fit the bill. They do a broccoli and stilton soup at Sainsburys (I think Sainsburys own) which is nice and thick and only 10 grams per half tin.
Home-made soups are really easy to make and transport and you can be in charge of the carb and taste content.
I use leftover veggies etc that look a bit wrinkly before I visit the supermarket etc+ fresh ones.
Soups can be thick or thin - blitz half or not.
It's easy to add flaxseeds/ wheatgerm etc for extra vitality.
Cost is minimal. Taste is so much better.
My wife normally makes her own soup,but she always says you cannot beat Heinz Tomato Soup,so through the winter months we usually share a can about three times a week with wholemeal bread.