After the 2017 merger Lucens had an area of 19.28 km² (7.44 sq mi).

Before the merger Lucens had an area, (as of the 2004/09 survey) of 7.83 square kilometers (3.02 sq mi).
 Of this area, about 42.9% is used for agricultural purposes, while 36.8% is forested.
Of the rest of the land, 18.0% is settled (buildings or roads) and 2.3% is unproductive land.
 In the 2013/18 survey a total of 94 ha (230 acres) or about 12.0% of the total area was covered with buildings, an increase of 32 ha (79 acres) over the 1981 amount.
 Over the same time period, the amount of recreational space in the municipality decreased by 1 ha (2.5 acres) and is now about 0.38% of the total area.
 Of the agricultural land, 3 ha (7.4 acres) is used for orchards and vineyards, 340 ha (840 acres) is fields and grasslands.
 Since 1981 the amount of agricultural land has decreased by 28 ha (69 acres).
 Over the same time period the amount of forested land has decreased by 5 ha (12 acres).
 Rivers and lakes cover 18 ha (44 acres) in the municipality.

The municipality was part of the Moudon District until it was dissolved on 31 August 2006, and Lucens became part of the new district of Broye-Vully.

The municipality is located along the left bank of the Broye.

The municipality of Oulens-sur-Lucens will merge on 1 July 2011 into the municipality of Lucens.
After the 2017 merger Lucens had an area of 19.28 km² (7.44 sq mi).
Before the merger Lucens had an area, (as of the 2004/09 survey) of 7.83 square kilometers (3.02 sq mi).  Of this area, about 42.9% is used for agricultural purposes, while 36.8% is forested. Of the rest of the land, 18.0% is settled (buildings or roads) and 2.3% is unproductive land.  In the 2013/18 survey a total of 94 ha (230 acres) or about 12.0% of the total area was covered with buildings, an increase of 32 ha (79 acres) over the 1981 amount.  Over the same time period, the amount of recreational space in the municipality decreased by 1 ha (2.5 acres) and is now about 0.38% of the total area.  Of the agricultural land, 3 ha (7.4 acres) is used for orchards and vineyards, 340 ha (840 acres) is fields and grasslands.  Since 1981 the amount of agricultural land has decreased by 28 ha (69 acres).  Over the same time period the amount of forested land has decreased by 5 ha (12 acres).  Rivers and lakes cover 18 ha (44 acres) in the municipality.
The municipality was part of the Moudon District until it was dissolved on 31 August 2006, and Lucens became part of the new district of Broye-Vully.
The municipality is located along the left bank of the Broye.
The municipality of Oulens-sur-Lucens will merge on 1 July 2011 into the municipality of Lucens.
Lucens