Most pediatric drug doses are calculated based on **body weight** because children metabolize medicines differently than adults. Here's how it works.
The Basic Formula
Dose per dose = Weight (kg) × Dose per kg
For example, if a drug is prescribed at 10 mg/kg and your child weighs 12 kg:
• Dose = 12 × 10 = **120 mg**
Step-by-Step Example: Paracetamol for 12 kg Child
1. Find the dose: Paracetamol = 10–15 mg/kg
2. Multiply: 12 kg × 15 mg = 180 mg (maximum single dose)
3. Convert to ml (if syrup): 180 mg ÷ 24 mg/ml = 7.5 ml
4. Check max daily: 60 mg/kg × 12 kg = 720 mg/day max
Important Rules
1. **Never estimate** — always use the actual weight
2. **Check the concentration** — different syrups have different strengths
3. **Know the max dose** — each drug has a daily limit
4. **Use proper measuring tools** — syringes, not household spoons
mg vs ml — Why It Matters
Drug labels show dose in **mg** (milligrams) but you measure in **ml** (millilitres). Always check:
• What is the **concentration**? (e.g., 120mg/5ml)
• How many **mg per ml**? (e.g., 24mg/ml)
Formula: **ml = mg ÷ concentration per ml**
Use our [pediatric dose calculator](/) — it does all this automatically based on your child's weight.