Rule of Nines

The rule of nines is a standardized method used to quickly assess how much body surface area (BSA) has been burned on a patient. This rule is only applied to partial thickness (2nd degree) and full thickness (3rd degree) burns. The diagram below depicts BSA percentages for adults and infants of one year or less. For children over the age of one year, please see the formula below.


For children over the age of one year, for each year above one, add 0.5% to each leg and subtract 1% for the head. This formula should be used until the adult rule of nines values are reached. For example, a 5-year old child would be +2% for each leg and -4% for the head.

An alternative method to calculating the BSA is to compare it to the size of the patient’s palm, which equates to approximately 1% BSA. For example, if a burn area is the size of (5) palm surfaces, the burn would be roughly 5% BSA. This method can be used to estimate the BSA for both adults and pediatrics. In most cases, you may find it more useful to use the rule of nines when evaluating larger burn areas and the “palm” method for smaller burn injuries.


  1. beth jackson says

    WHERE can i order rule of 9 posters and pocket cards for EMT and hospital ED usE?. thank you, Beth

  2. Andy says

    please what percentages of burns in adults will it be:
    1. crutical
    2. fair
    3. good
    4. poor

    can u pls help me in children too????

  3. Katie says

    Are we permitted to crop and use the adult “rule of nines” image for research reference purposes? Or is there a proper process for gaining access to the image? Thanks!

    • says

      Hi Katie,

      Yes, you may use the image for research purposes and we appreciate you asking for permission.

    • Eugene says

      This has been in use in EMS for decades. It’s a great system, simple and quick for estimating the burn coverage of a burn victim IN THE FIELD. It only applies to 2nd degree burns or greater.

      As to it’s name, notice that on the adult everything but the “critical 1%” is 9% or a simple multiple of 9%. Small children are short in the leg, and “top heavy” so the percentages are changed. Even then, applying the rule of nines to a young child is a great start.

      Generally speaking, burns covering more than 10% of the body are considered “critical,” as are • Burns that cover the hands, feet, face, groin, buttocks or a major joint
      • Chemical or electrical burns
      • Third- or fourth-degree burns [also sometimes called “full thickness” burns]
      • Difficulty breathing or burns to the airway

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