Chapel Hill is about 4.1 times smaller than Des Moines.

Des Moines (map shows its 58 named neighbourhoods; the area covers the whole city) is approximately 228 sq km, while Chapel Hill is approximately 56 sq km, making Chapel Hill 24.61% the size of Des Moines.
Tip: This to-scale comparison of Des Moines vs. Chapel Hill 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.