It depends on the size of the tube of toothpaste.
But I brush my teeth twice per day and out of the large size tube of toothpaste I can brush my teeth for 2 months before I run out of toothpaste.
So averaging 30 days in a month that means I can brush my teeth 120 times out of a large tube of toothpaste.
When brushing your teeth you only need a small amount of toothpaste on the toothbrush to get your teeth properly cleaned.
Some people may use more toothpaste than others so you may go through one tube of toothpaste faster than someone else.
I've heard that some people have one tube of toothpaste last them up to a year which is reasonable depending on how often they brush there teeth.
Some people may only brush their teeth every few days or once per week which is better than not brushing their teeth at all.
But it's best to brush your teeth daily or twice per day to keep your teeth clean and healthy.