Measure growth percentiles using corrected age easily. Assess weight, length, head size, and BMI together. Spot trends early with organized outputs and helpful guidance.
Use one or more measurements. When weight and length are both entered, BMI percentile is calculated automatically.
These sample rows illustrate typical inputs and the kind of outputs produced by the calculator.
| Sex | Age (months) | Weight (kg) | Length (cm) | Head (cm) | BMI | Illustrative outcome |
|---|---|---|---|---|---|---|
| Male | 2.0 | 5.80 | 59.00 | 39.20 | 16.66 | Most measurements near the middle percentiles. |
| Female | 4.5 | 6.20 | 62.80 | 40.90 | 15.72 | Weight slightly lower, length near median. |
| Male | 9.0 | 9.70 | 72.00 | 45.10 | 18.71 | Weight and BMI trend into higher bands. |
| Female | 12.0 | 8.60 | 73.50 | 44.70 | 15.92 | Balanced pattern around expected range. |
| Male | 18.0 | 10.10 | 79.50 | 47.00 | 15.98 | Weight lower than median, length also lower. |
The calculator uses an LMS-style growth method. For each measurement, age and sex select interpolated L, M, and S values from the built-in reference curves.
z = ((value / M)L - 1) / (L × S)z = ln(value / M) / S
Percentile conversion: percentile = normal cumulative distribution of the z-score × 100.
BMI formula: BMI = weight (kg) ÷ [length (m)]².
Corrected age: corrected age = actual age − (weeks early ÷ 4.345).
A percentile shows how a baby’s measurement compares with peers of the same sex and age. For example, the 60th percentile means the measurement is greater than about 60 percent of comparable babies.
Not always. Some babies naturally track along lower curves. Clinicians usually focus on the overall growth pattern, feeding history, health status, and whether percentiles are changing sharply over time.
BMI can add context when both weight and length are available. It is another screening measure, not a diagnosis, and should be interpreted together with other growth measures and clinical judgment.
Corrected age is commonly used for babies born preterm when growth and development are being reviewed. This calculator lets you apply a simple correction using the number of weeks early.
No. This version is designed for ages 0 to 24 months. Older children should be assessed with age-appropriate growth references and clinical guidance.
A single result is only a snapshot. Repeated measurements help reveal growth velocity, steady tracking, or meaningful percentile changes that deserve closer review.
Yes. Small errors in infant length, weight, or head circumference can shift percentile estimates. Careful measurement technique improves usefulness and consistency.
No. This calculator is for educational screening and record review. Discuss concerns, poor feeding, illness, or rapid percentile changes with a pediatric professional.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.