The Stunting Calculator helps parents check whether their child's height meets WHO growth standards.
Compares the child's height against the median and -2 SD (Standard Deviation) threshold based on age and sex. Children below -2 SD are classified as stunted, and below -3 SD as severely stunted. Supports ages 0-19 years.
Disclaimer: This calculator is for initial screening. An official stunting diagnosis should be made by a healthcare professional with standardized anthropometric measurements.
Calculator information
📋 How to use this calculator
- Select the child's sex (male or female) because the WHO growth curves differ by sex.
- Enter age in months (0-228 months / 0-19 years), measured from birth to the date of measurement.
- Enter height in cm. For children under 2, measure length lying down; over 2, measure standing height.
- Click Calculate to see the height-for-age Z-score and its nutritional status category.
- Interpret the classification: normal (>= -2 SD), stunted (< -2 SD), severely stunted (< -3 SD).
- If results show stunting, consult a pediatrician, WIC clinic, or public health nurse for targeted nutritional intervention.
🧮 WHO Height-for-Age Z-score (HAZ)
Z = (Height_child - Reference_median) / Reference_SD
- Height_child = child's height/length (cm)
- Reference_median = median height at the given age and sex from the WHO 2006/2007 standards
- Reference_SD = 1 standard deviation from the reference median
Standard WHO classification: Normal -2 SD to +3 SD; Stunted -3 SD to <-2 SD; Severely stunted <-3 SD; Tall >+3 SD.
💡 Worked example: Boy aged 24 months, height 80 cm
Given:- Sex = Male
- Age = 24 months
- Height = 80 cm
- WHO median for 24-month-old boys = 87.1 cm; 1 SD = 3.1 cm
Steps:- Compute the difference: 80 - 87.1 = -7.1 cm
- Divide by SD: -7.1 / 3.1 = -2.29
- Z-score = -2.29 SD
- Because Z < -2 SD but still > -3 SD, the child falls into the Stunted category
Result: Nutritional status: STUNTED (-2.29 SD). Needs evaluation of feeding patterns, history of recurrent infections, and a targeted nutrition plan per CDC/AAP guidance.
❓ Frequently asked questions
What is the difference between stunting and acute malnutrition?
Stunting is a failure of linear growth (chronic shortness) caused by long-term undernutrition, measured by height-for-age. Acute malnutrition is measured by weight-for-height and reflects recent undernutrition. Stunting can become permanent if not corrected before age 2, while acute malnutrition can recover more quickly with nutritional therapy. The two conditions are distinct but can co-occur in the same child.
How common is stunting in the United States?
Stunting prevalence in the U.S. is low overall (~2-3%) but is elevated among children from low-income households, certain immigrant communities, and those with chronic disease. The WHO categorizes prevalence under 2.5% as 'eliminated' and considers 20%+ as 'high.' Federal programs such as WIC, SNAP, and school meals are core tools for prevention. The CDC recommends WHO growth charts for ages 0-2 and CDC charts thereafter.
Is stunting reversible?
Stunting detected before age 2 (within the first 1,000 days of life) can often be improved with adequate nutrition intervention. After age 2, effects on final height and cognitive development tend to be permanent, though continued good nutrition still optimizes outcomes. Early detection through routine pediatric well-child visits is therefore critical. Prevention focuses on maternal nutrition during pregnancy and infants 0-24 months.
What are the main causes of stunting?
Direct causes are inadequate nutrient intake (especially animal protein, iron, zinc) and repeated infections (diarrhea, respiratory infections). Indirect causes include suboptimal feeding practices, poor sanitation, limited access to clean water, and weak maternal-child health services. Risk factors include low birth weight, maternal undernutrition, lack of exclusive breastfeeding, and inadequate complementary feeding. Stunting is multifactorial.
How often should height-for-age be measured?
The AAP recommends growth measurements at every well-child visit: at 2-4 weeks, 2, 4, 6, 9, 12, 15, 18, and 24 months, then annually. Results are plotted on WHO growth charts (0-2 years) and CDC growth charts (2+ years). School-aged children should be measured at least annually through school health programs. If growth flattens for 2 consecutive visits, refer to a pediatrician promptly.
📚 Sources & references
Last updated: May 11, 2026