Burn area is the percentage of the skin burn area to the whole body surface area (TBSA). At present, the following methods are used in China to estimate the burn area: (1) Palm method: This method is to put the five fingers of the hand together regardless of age and sex, which is 1% of one’s own body surface area. (2) The ten-point method. (3) Chinese nine-point method. The decimal method and the Chinese nine-point method are used to estimate the burn area by dividing the body surface into a number of equal parts. What must be noted when estimating the area of burns? (1) No matter which method is used, although it is an estimate, it should be approximated and recorded in whole numbers, and the number of decimal points should be rounded off, i.e., less than 1% of the area is recorded as 1%. (2) estimate the total area of burns, shallow Ⅱ degree, deep Ⅱ degree and Ⅲ degree burns area should be calculated separately, and then add up to the total area, not counting Ⅰ degree burns. (3) Inhalation injuries (respiratory burns) are not calculated area, but the severity (mild, moderate, severe) must be indicated in the diagnostic center. (4) Large area burns can be estimated first normal skin area, and then subtract the normal skin area from the entire body surface area, which is the total area of the burn. (5) Estimation of burn area by the palm method is based on the casualty’s hand, which can be measured directly by the examiner’s hand if it is similar in size to the casualty’s hand.