Rome is about 4.1 times bigger than Henderson.

Henderson (map shows its 23 named neighbourhoods; the area covers the whole city) is approximately 313 sq km, while Rome is approximately 1,287 sq km, making Rome 311% larger than Henderson.
Tip: This to-scale comparison of Henderson vs. Rome 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.