Vertically center element on HTML page with some content on top (Bootstrap)

Kristof Hi there. A search would have probably given you a answer on how to do this.
He is a Fiddle that will do what you want to do here.

.centerthis {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  margin: auto;  
}