Thyroid Laboratory Ranges1


Total T3 (Triiodothyronine)
Ageng/dLnmol/L
Newborn7.5 - 2601.16 - 4.00
1-5 years100 - 2601.54 - 4.00
5-10 years90 - 2401.39 - 3.70
10-15 years80 - 2101.23 - 3.23
> 15 years155 - 1901.77 - 2.93

Total T4 (Thyroxine)
Ageµgr/dLnmol/L
1-3 days8.2 - 19.9106 - 256
1 week6.0 - 15.977 - 205
1-12 months6.1 - 14.979 - 192
1-3 years6.8 - 13.588 - 174
3-10 years5.5 - 12.871 - 165
> 10 years4.2 - 13.054 - 167

TSH (Thyroid Stimulating Hormone)
AgeTarget Range (µIU/L)
2-20 weeks1 - 28.9
5 months-20 years0.3 - 3.03

Operational criteria for thyroid disorders2
  Free T4 TSH
Hypothyroidism Low (<9pmol/L) High (>5mU/L)
Hypothyroidism
(subclinical/compensated) 
 Normal (9-24pmol/L)  High (>5mU/L)
Hyperthyroidism High (>9pmol/L)  Low (<0.5mU/L)