Indianapolis is about 1.6 times bigger than Madrid.

Madrid is approximately 604 sq km, while Indianapolis is approximately 935 sq km, making Indianapolis 55% larger than Madrid.
Tip: This to-scale comparison of Madrid vs. Indianapolis uses the Mercator projection, which distorts the size of regions near the poles.
Our free app, MapSize by MyLifeElsewhere — compare any two places, to scale on your mobile device.