I only use time as a rough guide. The thickness of the burger, the variations in frying pans, the characteristics of different grills and fuels, etc., etc just don't allow for an exact time that always works.
I gently press the burger with my finger for me and DH or the spatula for anyone else. The resilience of the meat tells you how well done it is. I do that for steaks and chops too. It takes practice to learn to recognize how resilient you want the meat.
May you live as long as you wish and love as long as you live.
Robert A. Heinlein