Sils im Engadin/Segl has an area, (as of the 2004/09 survey) of . Of this area, about 25.9% is used for agricultural purposes, while 11.1% is forested. Of the rest of the land, 1.2% is settled (buildings or roads) and 61.7% is unproductive land. In the 2004/09 survey a total of or about 0.6% of the total area was covered with buildings, an increase of over the 1985 amount. Over the same time period, the amount of recreational space in the municipality increased by and is now about 0.16% of the total area. Of the agricultural land, is fields and grasslands and consists of alpine grazing areas. Since 1985 the amount of agricultural land has decreased by . At the same time the amount of forested land has increased by . Rivers and lakes cover in the municipality.