About the hydroxychloroquine dose calculator
This calculator applies the American Academy of Ophthalmology's (AAO) 2016 revised hydroxychloroquine dosing guideline. It compares a prescribed daily dose against a maximum of 5 mg per kilogram of real (actual) body weight per day, then reports the corresponding tablet count. It performs arithmetic only and is intended for educational reference, not for adjusting a prescription.
How the maximum dose is calculated
The guideline maximum equals real body weight in kilograms multiplied by 5 mg. If weight is entered in pounds, it is first converted to kilograms (1 kg = 2.20462 lb). This 5 mg/kg/day real-body-weight threshold replaced an older rule of 6.5 mg/kg of ideal body weight, which tended to overstate the safe dose for people whose actual weight is above their ideal weight, since ideal body weight is always the lower of the two figures for that group.
Interpreting values
- The percent-of-max figure compares the prescribed daily dose to the calculated guideline maximum; values above 100% mean the prescribed dose exceeds the mg/kg cap for that body weight.
- The dose-per-kilogram figure is the prescribed daily dose divided by body weight, useful for comparing directly against the 5 mg/kg/day threshold.
- The tablets-per-dose figure divides the daily dose by doses-per-day and the selected tablet strength; real prescriptions are usually rounded to whole or half tablets by the dispensing pharmacy.
Important disclaimer
This tool does not diagnose retinopathy risk and does not account for treatment duration, kidney or liver function, concurrent medications, or baseline eye disease. It does not constitute medical advice. Dosing decisions should be made by a licensed clinician managing the underlying condition, together with the recommended baseline and periodic eye examinations.