Oral Liquid Medication Dose Calculator
Convert a weight-based oral liquid prescription into a dose volume and estimate the quantity required for a course.
Version 1.0.0
Prescription
kg
mg/kg/day
doses/day
Available liquid and course
mg
mL
mL
days
Available concentration: —
Dose
—
mg per dose
Volume
—
mL per dose
Days per bottle
—
days
Bottles needed
—
whole bottles
No clinical values are intentionally saved by this control.
Equations
Available concentration
Concentration (mg/mL) = medication amount (mg) ÷ liquid volume (mL)Total daily medication dose
Daily dose (mg/day) = patient weight (kg) × prescribed dose (mg/kg/day)Medication per dose
Dose (mg) = daily dose (mg/day) ÷ doses per dayDaily liquid volume
Daily liquid volume (mL/day) = daily dose (mg/day) ÷ concentration (mg/mL)Liquid volume per dose
Volume (mL) = dose (mg) ÷ concentration (mg/mL)Days supplied by one bottle
Days per bottle = bottle size (mL) ÷ daily liquid volume (mL/day)Whole bottles required
Bottles = ceiling[daily liquid volume (mL/day) × course length (days) ÷ bottle size (mL)]Intermediate values are not rounded. Displayed dose is rounded to the nearest whole mg. Positive concentration, dose-volume and days-per-bottle outputs use one decimal place at values ≥0.1; smaller positive values use up to six decimal places, with scientific notation only below that display resolution, so an accepted positive quantity is never displayed as zero.
References
- Bureau International des Poids et Mesures. The International System of Units (SI). 9th ed. Sèvres: BIPM; revised 2026. doi:10.59161/AUEZ1291. DOI: 10.59161/AUEZ1291