Thyroid

Free T3 unit converter

Active thyroid hormone (triiodothyronine)

Also known as: Free triiodothyronine, T3L, Freies Trijodthyronin, Triiodothyronine libre, T3 libre, Triyodotironina libre

Converter

Enter a value in any unit and all other units fill in.

pg/mL pmol/L ng/dL

Worked example

5 pmol/L (middle of the reference range) = 3.26 pg/mL

Conversion formulas

pg/mL	pg/mL = pmol/L × 0.651	pmol/L = pg/mL × 1.536
ng/dL	ng/dL = pmol/L × 0.0651	pmol/L = ng/dL × 15.36

Reference range

Unit	Adults
pg/mL	2.083 – 4.427
pmol/L	3.2 – 6.8
ng/dL	0.2083 – 0.4427

Source: MedlinePlus (NLM): T3 test · Last reviewed: 2026-10-14

Note from the source: 210-440 pg/dL (3.2-6.8 pmol/L); age-specific below 20 years (MedlinePlus)

Frequently asked questions

How do I convert Free T3 from pmol/L to pg/mL?

pg/mL = pmol/L × 0.651. In the other direction: pmol/L = pg/mL × 1.536.

What is the reference range of Free T3?

For adults the range is 3.2 – 6.8 pmol/L (MedlinePlus (NLM): T3 test). Reference ranges differ between laboratories and partly by sex and age; use the range printed on your lab report.

Which units are used for Free T3?

Common units are pg/mL, pmol/L, ng/dL.