Levothyroxine Starting Dose

Calculate levothyroxine replacement dose: healthy adult hypothyroidism 1.6 mcg/kg/day; elderly or cardiac disease start 12.5-25 mcg/day; post-thyroidectomy may need 2.0 mcg/kg/day.

Weight
Height
Clinical Guidance

BMI is a screening measure of body size, not a direct measure of body fat. The standard WHO categories are underweight (<18.5), normal (18.5–24.9), overweight (25–29.9), and obese (≥30).

BMI can overestimate body fat in athletes with high muscle mass and underestimate it in older adults with low muscle mass. Interpret it alongside waist circumference and clinical context rather than as a standalone diagnosis.

⚕ Clinical Disclaimer: These calculators are for educational and reference purposes only. Always verify results with qualified clinical judgment and current clinical guidelines. Do not use as a sole basis for medical decisions.
Advertisement

How to Use

Enter the values for the scenario you are assessing. Calculate levothyroxine replacement dose: healthy adult hypothyroidism 1.6 mcg/kg/day; elderly or cardiac disease start 12.5-25 mcg/day; post-thyroidectomy may need 2.0 mcg/kg/day. Use the levothyroxine dose result to inform your calculation.

Related Calculators

TSH Zones

Medical

T3/T4 Conversion

Medical

Vitamin D Status

Medical

Frequently Asked Questions