Büren an der Aare had an area, (as of the 2004/09 survey) of . Of this area, about 46.2% is used for agricultural purposes, while 34.4% is forested. Of the rest of the land, 11.7% is settled (buildings or roads) and 7.6% is unproductive land. Of the unproductive land, or 7.1% is either rivers or lakes and or 0.6% is unproductive land. Over the past two decades (1979/85-2004/09) the amount of land that is settled has increased by and the agricultural land has decreased by .