how many nanometers in a kilometer?
<answer> 1,000,000,000,000 <context> The following is a list of definitions relating to conversions between nanometers and kilometers. A nanometer is a unit of Length or Distance in the Metric System. The symbol for nanometer is nm. There are 1,000,000,000,000 nanometers in a kilometer. The International spelling for this unit is nanometre.