The rule-of-nines is a quick method to assess the extent of burn injury in an adult. To calculate the extent of the burn count:
- 9% for both the anterior and posterior surfaces of the head and neck
- 9% for both the anterior and posterior surfaces of each upper limb (18% for both)
- 18% anterior trunk; 18% posterior trunk; 36% for both anterior and posterior trunk.
- 9% for anterior, 9% for posterior surface of each limb (36% total for both lower limbs)
- 1% for perineum
