Disclaimer: This is the world of the trauma specialist. They know what they’re doing. This is only for general education purposes.

How To Calculate Burn Percentage

Here’s the general equation for calculating the percentage of body that has been burned.

Rule of 9s: 18 on back, 18 on front, 9 head, 9 arm, 9 leg; 18 child head

Once the percentage of body burned is calculated, another formula allows the clinician to calculate how much fluids will need to be replaced.

4 x SA x kg = ml NS, First 1/2 in 8H

Four times the surface area calculated by the rule of nines above
times the patient’s weight in kilograms…

Will yield the amount of cc of normal saline that needs to be replaced by IV.

The first half of that must be replaced in eight hours.