Here's how to convert micrograms (µg) to kilograms (kg):

* 1 microgram (µg) = 1 x 10^-9 grams (g)

* 1 gram (g) = 1 x 10^-3 kilograms (kg)

Therefore:

1 µg = (1 x 10^-9 g) * (1 x 10^-3 kg/g) = 1 x 10^-12 kg

So, 1 microgram is equal to 1 x 10^-12 kilograms.