Pediatric Kidney Size Calculator

About This Calculator

This calculator provides ultrasound-based kidney length reference ranges for children from birth (0 months) to 18 years. Two normative datasets are used:

• 0 – 11 months: Month-specific values from Han & Babcock (1985) and Blane et al. (1985). Sex differences are negligible at this age, so combined values are used.

• 1 – 18 years: Sex-specific percentile tables (2.5th, 50th, 97.5th) from Obrycki et al. (2022), the largest multicenter European study (n = 1,758 healthy children), with linear interpolation between yearly data points.

References (Vancouver Style)

1. 1. Obrycki Ł, Sarnecki J, Ostalska-Nowicka D, Tkaczyk M, Leszczyńska B, Mizerska-Wasiak M, et al. Kidney length normative values in children aged 0–19 years — a multicenter study. Pediatr Nephrol. 2022;37(4):811–820. doi: 10.1007/s00467-021-05297-y. PMCID: PMC9023417.
2. 2. Han BK, Babcock DS. Sonographic measurements and appearance of normal kidneys in children. AJR Am J Roentgenol. 1985;145(3):611–616. doi: 10.2214/ajr.145.3.611.
3. 3. Blane CE, Bookstein FL, DiPietro MA, Teele RL. Sonographic standards for normal infant kidney length. AJR Am J Roentgenol. 1985;145(6):1289–1291. doi: 10.2214/ajr.145.6.1289.
4. 4. Rosenbaum DM, Korngold E, Teele RL. Sonographic assessment of renal length in normal children. AJR Am J Roentgenol. 1984;142(3):467–469. doi: 10.2214/ajr.142.3.467.

Normative Data Summary

Obrycki et al. (2022) derived percentile curves using the LMS method from 1,758 children. Kidney length at birth is ~60 mm (male) and ~57 mm (female), rising to ~114 mm and ~105 mm respectively at age 18. A height-based formula is also available:

Median (mm) = 0.5 × height (cm) + 28.2
Upper limit (97.5th %ile) = 0.5 × H + 34.8
Lower limit (2.5th %ile) = 0.4 × H + 20.4