After about 10 to 15 minutes of cooking time, check the burger for doneness. Place an instant-read in the center of the thickest burger.
According to the USDA, ground meat must be cooked to at least 160°, or well done. This typically takes from 10 to 15 minutes, depending on the thickness or size of the hamburgers.
After using the food thermometer, clean it with hot soapy water.
Though any temperature under 160° is not considered safe for ground meat (USDA Guidelines), here is a list of cooking times for varying degrees of doneness for burgers:
Burgers With Caramelized Onions
Juicy Grilled Burgers