There are 1,000,000,000,000 picometres in one metre. Therefore, one picometre is equal to 1/1000000000000 = 0.000000000001 metres.

Using the short scale, 1 billionth of a millimetre = 10⁻⁹ × 10⁻³ m = 10⁻¹² m = 1 pm = 1 picometre

Using the long scale, 1 billionth of a millimetre = 10⁻¹² × 10⁻³ m = 10⁻¹⁵ m = 1 fm = 1 femtometre

1 picometre is equal to 1 x 10-12 metres, or one trillionth of a metre.

1. But you can go to smaller units than a micrometre: for example a nanometre, a picometre etc.

A picometre is a unit of measurement equivalent to one trillionth (1/1000000000000) of a metre. It is abbreviated pm.