Version July 2025
The MUAC is an accurate and efficient way to screen for wasting. The measurement is taken with a standard measuring tape, which is usually color coded to indicate the degree of wasting. The measurement should be done with the child standing or sitting upright or held upright by a caregiver, with the arm relaxed and hanging down and the measuring tape lying flat but not tight against the skin*.
For children 6 to 59 months old, the measurement is used to define[1]:
(A) Moderate wasting, indicated by MUAC 11.5 to 12.4 cm (indicated by the yellow area on the standard measuring tape).
(B) Severe wasting, indicated by MUAC <11.5 cm (indicated by the red area on the standard measuring tape).
For infants 6 weeks to <6 months of age, MUAC <11.0 cm is one indicator of at least moderate malnutrition (ie, risk for poor growth and development).
MUAC: mid-upper arm circumference.
* Either the right or left arm may be used when screening for malnutrition in the field. Although the World Health Organization dataset was developed using measurements on the left arm, there is high concordance between the left and right arms in infants and young children[2]. Similarly, measurements in the field can be taken by using visual approximation to identify the midpoint between the top of the shoulder and the elbow[2], although the original description of how to measure MUAC instructed precise measurements of the point midway between the acromion (tip of the shoulder blade) and olecranon (tip of the elbow).