A Glicko rating is converted to kyu/dan rank using the formula rank = ln(rating / 525) * 23.15. Source
That equation was designed so that each player in a handicap game has a roughly equal chance of winning. (That’s the the goal of the integer kyu/dan rank system.) As rank increases, the rating points gap between each rank gets larger – each handicap stone is “worth more”. This is because the stronger the player, the better he uses each stone.