https://blendermarket.com/products/render-time-estimation-add-on

If you are someone who likes to manage your time, who prefers knowing remaining time, by chance you like things expressed in numbers, then you are in the right place. This addon is made for you.  Our long-desired, missing add-on shows you the estimated remaining time for your renders or video sequences. Installed in the N-panel with its simple, clean design it perfectly fits in the Blender GUI.