138.7 centimeters is equivalent to 54.606 inches.
To put this measurement into perspective, here are a few comparisons to known objects of similar size:
-138.7 centimeters is slightly taller than the average height of a 10-year-old child (51 inches).
-138.7 centimeters is about the length of a standard twin size bed (approximately 75 inches long).
-138.7 centimeters is roughly the height of a kitchen countertop, which is typically 36 inches high.
-138.7 centimeters is just a few inches shorter than the average height of an adult male (70 inches).