To convert 21 stone into kilograms, we use the conversion factor where 1 stone equals 6.35029318 kilograms.
First, we multiply 21 stone by the conversion factor:
21 stone * 6.35029318 kilograms/stone = 133.35617678 kilograms
Rounded to two decimal places for simplicity, 21 stone is approximately 133.36 kilograms.
