Basal is exactly what your body needs, nothing more or less. It really is different for everyone, and comparing to others is only of limited value. Over the last three years we have seen my son’s basal needs change over time, so it is correct for that period of time that it works, and then it needs to be reevaluated to ensure it is still the right amount.
What we do to determine insulin duration is take a high (not a 300,more like a 200) then we treat with insulin and skip the next meal. Note when the insulin doesn’t appear to be lowering your blood sugar anymore. Do this 2 or 3 times and you should be able to get a good estimate for your personal insulin duration.
If you are using a pump, there are some other things you can do, i.e. play with the duration settings and see what works best for you, but this is a little more complicated.