Boston is about 1.2 times bigger than Tempe.

Tempe (map shows its 64 named neighbourhoods; the area covers the whole city) is approximately 104 sq km, while Boston is approximately 124 sq km, making Boston 20% larger than Tempe.
Tip: This to-scale comparison of Tempe vs. Boston 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.