Medical & Clinical
Medication Dose Calculator
Most weight-based medicine is simple arithmetic — but it's arithmetic where mistakes matter. Double-check yours here.
Weight-based dosing prescribes milligrams per kilogram of body weight: dose (mg) = mg/kg × weight (kg). A 10 mg/kg order for a 70 kg adult is 700 mg. Liquid volumes follow from the concentration. Interpretation belongs to your clinician — use these numbers to ask better questions.
Dose = mg/kg × kg.
Volume = dose ÷ concentration.
Double-check pediatric and high-alert drugs.
Calculate Your Medication Dose
Dose
What Is Medication Dose?
Weight-based dosing matches the dose to the patient — the standard for children, and for many adult drugs with narrow therapeutic windows.
The calculator converts an mg/kg order into a milligram dose, daily and weekly totals, and — with a concentration — the liquid volume to measure.
How It Is Calculated
Dose (mg) = mg/kg × weight (kg)
Volume (mL) = dose ÷ concentration (mg/mL)
Example: Example: 10 mg/kg for 70 kg → 700 mg per dose; at 100 mg/5 mL → 35 mL
Dosing sanity references
| Drug class | Typical range |
|---|---|
| Paracetamol (acetaminophen) | 10–15 mg/kg/dose |
| Ibuprofen | 5–10 mg/kg/dose |
| Amoxicillin (children) | 20–45 mg/kg/day divided |
| Gentamicin | 5–7 mg/kg once daily (renal-adjusted) |
Limitations
- This is arithmetic assistance, not prescribing — indications, renal function, and interactions change real doses.
- Pediatric doses require weight-appropriate references.
- Always confirm against the product's labeling.
Sources & Review
References used for this calculator’s formulas and thresholds:
Medication Dose FAQ
How do you calculate mg/kg doses?
Multiply: dose (mg) = mg/kg × weight in kg. A 10 mg/kg order for a 70 kg patient is 700 mg.
How do I convert a dose to millilitres?
Divide by the concentration: 700 mg ÷ 100 mg/5 mL = 35 mL.
Why are children dosed by weight?
Metabolism and drug clearance scale with body size, and children's weights span a 20-fold range — fixed doses would under- or over-dose badly.
Important disclaimer: Results are educational estimates, not a substitute for professional medical advice. Discuss your results with a qualified professional before making decisions.