1 kilo is equal to approximately 2.20462262 pounds. Therefore, 53.4 kilos in stone is:

$$53.4 \text{ kg} * \frac{1 \text{ stone}}{6.35029318\text{ kg}}$$

$$= \frac{53.4}{6.35029318} \text{ stone} = 8.41 \text{ stone}$$

Therefore, 53.4 kilos is approximately 8.41 stone.