Free T4 (FT4) result checker
Enter your Free T4 (FT4) result to see where it falls against the Canadian reference range of roughly 10–20 pmol/L — with a plain-English interpretation and what to check next. Always read it alongside your TSH.
— pmol/L
Medical disclaimer: This calculator is for general educational purposes only and does not constitute medical advice or a diagnosis. Results are estimates based on the values you enter and standard formulas and reference ranges, which vary between laboratories and between individuals. Always discuss your results with a qualified healthcare professional. If you are experiencing a medical emergency, call 9-1-1.
Free T4 rarely tells the whole story on its own. Interpret it alongside your TSH — enter your TSH in our TSH checker, or use the full thyroid panel interpreter to read TSH, Free T4 and anti-TPO antibodies together.
Get an endocrinologist to review your results — $45
Upload your thyroid or metabolic results and get a written opinion from a PGIMER/AIIMS-trained endocrinologist within 6 hours — what your numbers mean together, what to test next, and what to say to your GP. No referral needed.
Frequently asked questions
What is a normal Free T4 level in Canada?
Most Canadian labs use a Free T4 reference range of about 10–20 pmol/L, though ranges vary by laboratory. Free T4 should always be interpreted together with TSH — the two move in opposite directions in most thyroid conditions.
My Free T4 is low-normal — should I be treated?
A low-normal Free T4 with a raised TSH points toward hypothyroidism and often warrants treatment, especially with positive anti-TPO antibodies or symptoms. A low-normal Free T4 with a normal TSH is usually monitored. Request anti-TPO antibodies to clarify.
Can Ginie Health review my thyroid results?
Yes. A written opinion from a PGIMER/AIIMS-trained endocrinologist costs $45 CAD, delivered within 6 hours, with no referral needed — useful for interpreting your Free T4, TSH and antibodies together and knowing what to push for.