Nennigkofen had an area, as of 2009, of 4.62 square kilometers (1.78 sq mi).
 Of this area, 2.97 km² (1.15 sq mi) or 64.3% is used for agricultural purposes, while 1.11 km² (0.43 sq mi) or 24.0% is forested.
  Of the rest of the land, 0.36 km² (0.14 sq mi) or 7.8% is settled (buildings or roads), 0.13 km² (32 acres) or 2.8% is either rivers or lakes and 0.01 km² (2.5 acres) or 0.2% is unproductive land.

Of the built up area, housing and buildings made up 4.1% and transportation infrastructure made up 3.0%.
 Out of the forested land, 22.3% of the total land area is heavily forested and 1.7% is covered with orchards or small clusters of trees.
 Of the agricultural land, 46.3% is used for growing crops and 16.2% is pastures, while 1.7% is used for orchards or vine crops.
 All the water in the municipality is flowing water.

The former municipality is located in the Bucheggberg district.
 Nennigkofen and the neighboring municipality of Lüsslingen form the Bucheggberger Aare valley.
Nennigkofen had an area, as of 2009, of 4.62 square kilometers (1.78 sq mi).  Of this area, 2.97 km² (1.15 sq mi) or 64.3% is used for agricultural purposes, while 1.11 km² (0.43 sq mi) or 24.0% is forested.   Of the rest of the land, 0.36 km² (0.14 sq mi) or 7.8% is settled (buildings or roads), 0.13 km² (32 acres) or 2.8% is either rivers or lakes and 0.01 km² (2.5 acres) or 0.2% is unproductive land.
Of the built up area, housing and buildings made up 4.1% and transportation infrastructure made up 3.0%.  Out of the forested land, 22.3% of the total land area is heavily forested and 1.7% is covered with orchards or small clusters of trees.  Of the agricultural land, 46.3% is used for growing crops and 16.2% is pastures, while 1.7% is used for orchards or vine crops.  All the water in the municipality is flowing water.
The former municipality is located in the Bucheggberg district.  Nennigkofen and the neighboring municipality of Lüsslingen form the Bucheggberger Aare valley.
Nennigkofen