How this calculator works
Weight times the prescribed mg/kg rate gives a mass. A daily rate must be divided by the prescribed number of doses before calculating each dose. A per-dose rate must not be divided that way. Liquid volume is mass divided by the labelled mg/mL concentration. These are generic dimensional calculations with no drug recommendations, dose limits or organ-function adjustments. The result is an estimate for information only and is not medical advice.
Formula
Per-dose basis: dose(mg) = weight(kg) x rate(mg/kg/dose). Daily basis: dose = weight x rate(mg/kg/day)/doses per day. Daily total = dose x doses per day. Liquid mL = dose(mg)/concentration(mg/mL).
Worked example
For 70 kg and an already prescribed 5 mg/kg per dose, the arithmetic gives 350 mg per dose. If instead 5 mg/kg is the daily total divided into two doses, each dose is 175 mg. At 10 mg/mL, that is 17.5 mL.
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Frequently asked questions
Does this decide a dose?
No. Supply the exact prescription. The calculator cannot decide whether that rate, frequency or formulation is appropriate.
What if the bottle says 100 mg per 5 mL?
Divide 100 by 5 to enter 20 mg/mL. Confirm the label and units before using the result.
Can it apply a maximum dose?
No. It does no clinical dose selection or capping. Any prescription limits must be checked separately by the prescriber or pharmacist.