640 km is 397.678 miles.
The exosphere goes from about 400 miles (640 km) high to about 800 miles (1,280 km).
400 miles + 400 km = 648.548 miles or 1,043.736 km.
400 km is equivalent to approximately 248.55 miles.
Answer: 400 km = 248.548 mi.
400 kilometres is equal to a distance of 248.5 miles.1 km = 0.6214 miles
400 kilometers = ~248.55 miles.
248400 miles
400 miles = about 643.7 km
400km is 248.5 miles.
About 400 miles or 643 km
400 kilometers ≈ 248.548477 mi