The acreage estimator covers two square miles in 10 acre squares. Each 10 acre square has a dot in the center. you can use to dot as the include/exclude point, or you can use the dot to define 2.5 acre squares. Off to the side the tool also has a small section divided into 2 acre squares with center dots. Around the edges of the tool there are distance rulers marked in: chains, tenths of miles, and feet. The lower right corner has a 1km corner ruler for plotting UTM coordinates.