Medicine Dosage Calculator — Free Online
Calculate the correct medicine dosage based on patient weight, prescribed dose per kg, and medicine concentration. Supports mg, mcg, and ml units. 100% private, no sign-up.
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Total Dose Required
0 mg
Volume to Administer
0 ml
Calculation Breakdown
Patient weight--
Dose per kg--
Total dose (weight x dose/kg)--
Concentration--
Volume (dose / concentration)--
Always verify dosage with your doctor or pharmacist. This calculator is for educational purposes only.
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Frequently Asked Questions
Multiply patient weight (kg) by prescribed dose per kg to get total dose. Then divide by medicine concentration to get the volume to administer. For example: 70 kg x 5 mg/kg = 350 mg. At 50 mg/ml concentration, that is 7 ml.
mg (milligrams) and mcg (micrograms) are weight units. 1 mg = 1000 mcg. ml (milliliters) is a volume unit. Medicine concentration is weight per volume (e.g., 250 mg/5 ml). Divide dose in mg by concentration to get volume in ml.
Weight-based dosing ensures each patient gets the right amount based on body size. It is critical for children, elderly patients, and drugs with a narrow therapeutic window. Under-dosing may be ineffective; over-dosing can cause adverse effects.
No. This calculator is for educational purposes only. Always follow your doctor's or pharmacist's instructions. Dosage depends on many factors including age, kidney/liver function, other medications, and the specific condition.
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Last updated: June 2026