How to transform robot motor steps into X/Y coordinates?


I have a robot with two motors A and B connected to wheels 21.6mm in diameter. The motors move in steps, and there are twenty steps for each complete revolution of the wheel. To make the robot move forwards, I turn on A and B in the forward direction and have it rotate a number of steps. To make it move backwards, I turn on A and B in the reverse direction. To get it to turn left, I turn on A and turn off B. Similarly to get it to turn right, I turn off A and turn on B. Using this scheme, I can get the robot to move in any direction.

My question is this: is it possible to transform the steps of motor A and motor B into the X/Y coordinates for the robot? For example, if I move the robot forward 10 steps, turn right 10 steps and move forwards again 10 steps can I calculate the X/Y coordinates of the robot? Assume that the robot starts at point 0,0.