Jacksonville is about 31 times bigger than Newark.

Newark (map shows its 20 named neighbourhoods; the area covers the whole city) is approximately 63 sq km, while Jacksonville (map shows its 197 named neighbourhoods; the area covers the whole city) is approximately 1,935 sq km, making Jacksonville 2,995% larger than Newark.
Tip: This to-scale comparison of Newark vs. Jacksonville 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.