Estimating the Size of a Burn

Estimating the Size of a Burn

British Columbia Specific Information

Burns can be serious injuries. If you have a serious burn injury, call 9-1-1 right away. For more information, or if you are not sure if you should contact a health care provider, call 8-1-1.

According to the World Health Organization, a burn is considered serious if it:

  • covers more than 15% of the body surface of an adult;
  • covers more than 10% of the body surface of a child;
  • involves someone who is very young, elderly, in poor health, or who has a pre-existing medical condition such as diabetes;
  • is a third degree burn;
  • occurs on your face, hands, feet or genitals;
  • encircles your leg or arm; or
  • is associated with trauma.

 

Smoke inhalation is also a serious injury and requires medical attention right away. For more information, see the World Health Organization handout on the Management of Burns.

Overview

You can quickly estimate the size of a burn by using the "rule of nines." This method divides the body's surface area into percentages.

Estimating burn size in adults

See a picture of the "rule of nines" for adults.

  • The front and back of the head and neck equal 9% of the body's surface area.
  • The front and back of each arm and hand equal 9% of the body's surface area.
  • The chest equals 9% and the stomach equals 9% of the body's surface area.
  • The upper back equals 9% and the lower back equals 9% of the body's surface area.
  • The front and back of each leg and foot equal 18% of the body's surface area.
  • The groin area equals 1% of the body's surface area.

Estimating burn size in babies and young children

See a picture of the "rule of nines" for babies and young children.

  • The front and back of the head and neck are 21% of the body's surface area.
  • The front and back of each arm and hand are 10% of the body's surface area.
  • The chest and stomach are 13% of the body's surface area.
  • The back is 13% of the body's surface area.
  • The buttocks are 5% of the body's surface area.
  • The front and back of each leg and foot are 13.5% of the body's surface area.
  • The groin area is 1% of the body's surface area.

The "rule of palm" is another way to estimate the size of a burn. The palm of the person who is burned (not fingers or wrist area) is about 1% of the body. Use the person's palm to measure the body surface area burned.

It can be hard to estimate the size of a burn. If you think a burn is a certain size but you are unsure, it is best to discuss the size of the burn with your doctor.

Credits

Current as of: March 22, 2023

Author: Healthwise Staff
Medical Review:
William H. Blahd Jr. MD, FACEP - Emergency Medicine
Adam Husney MD - Family Medicine
Kathleen Romito MD - Family Medicine
Martin J. Gabica MD - Family Medicine