Square Nanometers to Square Kilometers: the quick answer
1 nm² = 1 × 10⁻²⁴ km²
1 square nanometer equals 1 × 10⁻²⁴ square kilometers
To convert square nanometers to square kilometers, multiply the value by 1 × 10⁻²⁴. To go the other way, multiply square kilometers by 1 × 10²⁴ to get square nanometers.