Free T4 unit converter
Convert free T4 between ng/dL, pmol/L and ng/L. Type in either box. The factors come from our catalog and are checked by code.
AI-verified against cited sources. Awaiting expert reviewLast reviewed 2026-10-03
1 ng/dL = 12.8722 pmol/L. Nothing you type here leaves your browser.
The conversion
- 1 ng/dL = 12.87 pmol/LFrom ng/dL to pmol/L: multiply by 12.87. Back again: divide by 12.87.
- 1 ng/dL = 10 ng/LFrom ng/dL to ng/L: multiply by 10. Back again: divide by 10.
Mass and molar units are linked by the molecular weight: 776.87 g/mol (thyroxine (T4), C15H11I4NO4). Source: PubChem, National Library of Medicine.
Common values
From zero to about twice the usual upper limit, plus the usual limits themselves.
| ng/dL | pmol/L | ng/L |
|---|---|---|
| 0.5 | 6.4 | 5 |
| 0.82 | 10.6 | 8.2 |
| 1 | 12.9 | 10 |
| 1.5 | 19.3 | 15 |
| 1.77 | 22.8 | 17.7 |
| 2 | 25.7 | 20 |
| 2.5 | 32.2 | 25 |
| 3 | 38.6 | 30 |
| 3.5 | 45.1 | 35 |
Usual ranges in each unit
What labs print as the reference range, by who was tested. Sources for each range are on the Free T4 page.
| Who | ng/dL | pmol/L | ng/L |
|---|---|---|---|
| 1–5 | 0.85–1.75 | 10.9–22.5 | 8.5–17.5 |
| 6–10 | 0.9–1.67 | 11.6–21.5 | 9–16.7 |
| 11–19 | 0.93–1.6 | 12–20.6 | 9.3–16 |
| 20+ | 0.82–1.77 | 10.6–22.8 | 8.2–17.7 |
| Women, pregnancy t1 | 0.9–1.4 | 11.6–18 | 9–14 |
| Women, pregnancy t2 | 0.7–1.3 | 9–16.7 | 7–13 |