After the merger, Langenthal has an area of 17.22 km² (6.65 sq mi).
Of this area, 3.43 km² (1.32 sq mi) or 23.8% is used for agricultural purposes, while 6 km² (2.3 sq mi) or 41.6% is forested.
Of the rest of the land, 4.96 km² (1.92 sq mi) or 34.4% is settled (buildings or roads), 0.04 km² (9.9 acres) or 0.3% is either rivers or lakes.

Of the built up area, industrial buildings made up 5.1% of the total area while housing and buildings made up 17.8% and transportation infrastructure made up 8.0%.
while parks, green belts and sports fields made up 2.9%.
Out of the forested land, 40.5% of the total land area is heavily forested and 1.1% is covered with orchards or small clusters of trees.
Of the agricultural land, 16.6% is used for growing crops and 6.2% is pastures.
All the water in the municipality is flowing water.

Untersteckholz had an area, as of 2009, of 2.83 km² (1.09 sq mi).
Of this area, 2.09 km² (0.81 sq mi) or 73.9% is used for agricultural purposes, while 0.59 km² (0.23 sq mi) or 20.8% is forested.
Of the rest of the land, 0.16 km² (0.062 sq mi) or 5.7% is settled (buildings or roads).

Of the built up area, housing and buildings made up 2.1% and transportation infrastructure made up 3.2%.
17.7% of the total land area is heavily forested and 3.2% is covered with orchards or small clusters of trees.
Of the agricultural land, 56.5% is used for growing crops and 14.1% is pastures, while 3.2% is used for orchards or vine crops.

The municipality is the largest settlement in the Langetental (Langeten Valley) and since 1997 it has been considered a city.
It consists of the old village of Langenthal, numerous expansions of the village core, the village of Schoren and since 2010, Untersteckholz.
After the merger, Langenthal has an area of 17.22 km² (6.65 sq mi). Of this area, 3.43 km² (1.32 sq mi) or 23.8% is used for agricultural purposes, while 6 km² (2.3 sq mi) or 41.6% is forested. Of the rest of the land, 4.96 km² (1.92 sq mi) or 34.4% is settled (buildings or roads), 0.04 km² (9.9 acres) or 0.3% is either rivers or lakes.
Of the built up area, industrial buildings made up 5.1% of the total area while housing and buildings made up 17.8% and transportation infrastructure made up 8.0%. while parks, green belts and sports fields made up 2.9%. Out of the forested land, 40.5% of the total land area is heavily forested and 1.1% is covered with orchards or small clusters of trees. Of the agricultural land, 16.6% is used for growing crops and 6.2% is pastures. All the water in the municipality is flowing water.
Untersteckholz had an area, as of 2009, of 2.83 km² (1.09 sq mi). Of this area, 2.09 km² (0.81 sq mi) or 73.9% is used for agricultural purposes, while 0.59 km² (0.23 sq mi) or 20.8% is forested. Of the rest of the land, 0.16 km² (0.062 sq mi) or 5.7% is settled (buildings or roads).
Of the built up area, housing and buildings made up 2.1% and transportation infrastructure made up 3.2%. 17.7% of the total land area is heavily forested and 3.2% is covered with orchards or small clusters of trees. Of the agricultural land, 56.5% is used for growing crops and 14.1% is pastures, while 3.2% is used for orchards or vine crops.
The municipality is the largest settlement in the Langetental (Langeten Valley) and since 1997 it has been considered a city. It consists of the old village of Langenthal, numerous expansions of the village core, the village of Schoren and since 2010, Untersteckholz.
Langenthal