Mid-Upper Arm Circumference (MUAC) Assessment
Mid-Upper Arm Circumference (MUAC) Assessment
Mid-Upper Arm Circumference (MUAC) is a simple, rapid screening tool used worldwide to identify acute malnutrition in children aged 6–59 months. Unlike weight-for-height, which requires both a scale and a measuring board, MUAC needs only a single colored tape — making it ideal for community-based screening in resource-limited settings. The WHO and UNICEF recommend MUAC as a primary screening tool for severe acute malnutrition (SAM).
According to UNICEF, MUAC screening identifies approximately 70–80% of children with severe acute malnutrition. A MUAC below 115 mm in a child 6–59 months indicates severe acute malnutrition (SAM), requiring immediate therapeutic feeding. A MUAC between 115–125 mm indicates moderate acute malnutrition (MAM), requiring supplementary feeding. These cutoffs are used globally by organizations including WHO, UNICEF, and the World Food Programme.
How to Measure MUAC
- Use a standard MUAC tape (color-coded: green, yellow, red zones)
- Find the midpoint of the upper left arm: measure from the acromion (shoulder bone) to the olecranon (elbow tip), mark the midpoint
- Wrap the tape snugly around the arm at the midpoint, without compressing the skin
- Read the measurement to the nearest 1 mm with the arm relaxed and hanging at the side
- Record in millimeters (mm)
Interpreting MUAC Results
- Green zone (> 125 mm): Normal — no acute malnutrition
- Yellow zone (115–125 mm): Moderate acute malnutrition (MAM) — supplementary feeding needed
- Red zone (< 115 mm): Severe acute malnutrition (SAM) — immediate treatment required
For children aged 5–14 years, some programs use age-specific MUAC-for-age Z-scores. However, the 115 mm and 125 mm cutoffs remain the most widely used and are validated for children 6–59 months.
MUAC Assessment Calculator
MUAC Assessment Calculator
Frequently Asked Questions
What is MUAC and why is it used?
Mid-upper arm circumference (MUAC) is a rapid, low-cost screening measure of acute malnutrition. It uses a simple color-coded tape around the upper arm and requires no scales or measuring boards, making it ideal for community screening in children aged 6-59 months.
What MUAC value indicates severe acute malnutrition?
A MUAC below 115 mm in a child aged 6-59 months indicates severe acute malnutrition (SAM) per WHO/UNICEF criteria and requires immediate therapeutic feeding and medical care.
What does a MUAC of 115-125 mm mean?
A MUAC between 115 and 125 mm indicates moderate acute malnutrition (MAM), which requires supplementary feeding and follow-up. Children in this range should be assessed for underlying illness and referred to a nutrition program.
How is MUAC measured correctly?
Measure the left upper arm midway between the acromion (shoulder tip) and olecranon (elbow tip), with the arm relaxed and hanging at the side. Wrap the tape snugly but not tightly, and read to the nearest 1 mm.
Authoritative Resources
Written by Dr. Sarah Williams, MD (Pediatrics) | Medically approved by Dr. Ahmed Raza, MD (Pediatrics) | Updated for 2026
Disclaimer: This calculator is for general informational purposes only and is not a substitute for professional medical advice. Always consult your pediatrician.
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