BIOL 134 Course Project Determining Leaf Surface Area By Hand Obtain 1cm grid graph paper. This can be printed online for free from many sites, just perform an online search for "1cm grid paper printable" or similar and print. Lay leaf to be measured on the grid paper and trace the outline. Count the number of full square centimeters. Estimate the area of the partial squares. One way to do this is to count a partial square if it is at least half covered by the leaf. Do not count partial squares if they are less than half covered. Do not include the area of the stem (petiole)