How much does mass slow down time?

In physics, if there is biggest mass then the slow down time is more and this effect is basically known as gravitation time dilation. This type of effect can easily be calculated from the different type of metric in the environment.

When some outsider observe then, this effect time seemed to be slowed down. It basically measure the overall amount of the time which elapse at observer distance. Therefore, this is the main concept of the mass slow down time.