Philadelphia is about 8 times bigger than Helena.

Helena (map shows its 6 named neighbourhoods; the area covers the whole city) is approximately 44 sq km, while Philadelphia is approximately 348 sq km, making Philadelphia 682% larger than Helena.
Tip: This to-scale comparison of Helena vs. Philadelphia 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.