Olsen 2010 Preterm Growth Calculator
Calculate Olsen 2010 preterm growth z-scores and percentiles for weight (grams), length, and head circumference using postmenstrual age from 23–41 weeks.
How to interpret Olsen 2010 preterm growth
The Olsen 2010 charts describe growth of preterm infants in U.S. NICUs (Pediatrix Medical Group database). Weight is typically entered in grams; length and head circumference in centimeters. Plot by postmenstrual age from 23 to 41 weeks.
Olsen and Fenton references can yield different percentiles for the same infant because they reflect different populations and methods. Follow your unit’s chosen reference for documentation and nutrition goals.
Sources and Reference Basis
Olsen 2010 LMS data are based on a large U.S. NICU cohort. Use for bedside percentile lookup; interpret with serial measurements and local NICU policy.
- Olsen IE et al. New intrauterine growth curves based on United States data. Pediatrics. 2010 Primary reference for Olsen 2010 preterm growth charts.
- Fenton 2013 calculator Alternative WHO-harmonized preterm reference.
- Gestational age calculator Compute PMA for chart entry.
Related Tools
Frequently Asked Questions
Olsen vs Fenton—which should I use?
Both are valid preterm references. Many NICUs standardize on Fenton 2013 or 2025; some units still use Olsen 2010. Match your local policy.
What units does Olsen weight use?
Enter weight in grams for the Olsen 2010 calculator. Length and head circumference use centimeters.