The drive from Mankato to Indianapolis is approximately 900 kilometers. You will travel south on I-35 and then east on I-74. The trip takes about 10 hours. You will pass through Chicago, which can be very busy. The route is mostly flat and easy to navigate.
Total Distance: 900 km driving distance, 800 km straight-line air distance.
Chicago traffic can be heavy; plan accordingly.
Spring and fall for pleasant weather.