at that rate{adv. phr.} At a speed like this or that; with progress like this or that.
John's father said that if John kept going at that rate he would never finish cutting the grass. So Johnny has a whole dollar! At this rate he'll be a millionaire. "Three 100's in the last four tests! At this rate you'll soon be teaching the subject," Tom said to Mary. [TahlilGaran] English Idioms Dictionary ▲