 There are a number of methods to determine the TBSA , including the Wallace rule of <unk> , Lund and <unk> chart , and <unk> based on a person 's palm size . The rule of <unk> is easy to remember but only accurate in people over 16 years of age . More accurate estimates can be made using Lund and <unk> charts , which take into account the different proportions of body parts in adults and children . The size of a person 's <unk> ( including the palm and fingers ) is approximately 1 % of their TBSA . 
