[1] The Lenzburg district has an area, as of 2009[update], of 102.71 square kilometers (39.66 sq mi).

Of the rest of the land, 20.16 km2 (7.78 sq mi) or 19.6% is settled (buildings or roads).

[2] The blazon of the district coat of arms is Argent a Hurt.

There were a total of 21,294 jobs (of at least 6 hours per week) in the district.

[5] From the 2000 census[update], 12,952 or 27.9% were Roman Catholic, while 23,937 or 51.6% belonged to the Swiss Reformed Church.