One nanometre is equal to

1. By definition, 1 nanometre ($\text{nm}$) $=10^{-9}\text{ m}$.2. To convert meters to centimeters, multiply by $10^2$ (since $1\text{ m}=100\text{ cm}$):
$$1\text{ nm}=10^{-9}\text{ m}=10^{-9}\times 10^2\text{ cm}=10^{-7}\text{ cm}$$