In adults and elderly persons, the normal findings for acid phosphatase are 0.13-0.63 U/L (Roy, Brower, Hayden; 37°C) or 2.2-10.5 U/L (SI units). Normal findings in children are 8.6-12.6 U/mL (30°C), while normal findings in newborns are 10.4-16.4 U/mL (30°C).