Oberägeri has an area, as of 2009, of 36.2 km² (14.0 sq mi).
 Of this area, 0.3 km² (0.12 sq mi) or about 0.8% is occupied with buildings and 1.04 km² (0.40 sq mi) or about 2.9% is roads or transportation infrastructure.
 About a third or 12.24 km² (4.73 sq mi) is used for agriculture, while 0.71 km² (0.27 sq mi) or about 2.0% is used for small gardens.
 Forests or other wooded areas cover 13.53 km² (5.22 sq mi) or about 37.4% of the municipality.
 Of the rest, 6.33 km² (2.44 sq mi) or about 17.5% is covered with water, including the Ägerisee, and 2.07 km² (0.80 sq mi) or about 5.7% is marsh or moorland.

The municipality is located in the eastern pre-alpine, high valley on the northern shores of the Ägerisee at an elevation of about 724 m (2,375 ft).
 It consists of the village of Oberägeri and the hamlets of Morgarten/Hauptsee and Alosen (at an elevation of 897 m (2,943 ft)) as well as scattered farm houses.
Oberägeri has an area, as of 2009, of 36.2 km² (14.0 sq mi).  Of this area, 0.3 km² (0.12 sq mi) or about 0.8% is occupied with buildings and 1.04 km² (0.40 sq mi) or about 2.9% is roads or transportation infrastructure.  About a third or 12.24 km² (4.73 sq mi) is used for agriculture, while 0.71 km² (0.27 sq mi) or about 2.0% is used for small gardens.  Forests or other wooded areas cover 13.53 km² (5.22 sq mi) or about 37.4% of the municipality.  Of the rest, 6.33 km² (2.44 sq mi) or about 17.5% is covered with water, including the Ägerisee, and 2.07 km² (0.80 sq mi) or about 5.7% is marsh or moorland.
The municipality is located in the eastern pre-alpine, high valley on the northern shores of the Ägerisee at an elevation of about 724 m (2,375 ft).  It consists of the village of Oberägeri and the hamlets of Morgarten/Hauptsee and Alosen (at an elevation of 897 m (2,943 ft)) as well as scattered farm houses.
Oberägeri