Calculator
Enter the patient profile, product strength, and spacing. Results appear above this form after submission.
Example data table
| Profile | Weight | Dose rule | Example single dose | Example liquid at 120 mg/5 mL | Daily ceiling |
|---|---|---|---|---|---|
| Child | 15 kg | 10 to 15 mg/kg | 150 to 225 mg | 6.25 to 9.38 mL | 1125 mg |
| Child | 25 kg | 10 to 15 mg/kg | 250 to 375 mg | 10.42 to 15.63 mL | 1875 mg |
| Adult | 65 kg | 500 to 1000 mg | 650 mg | 27.08 mL | 4000 mg |
Formula used
Child single dose: Weight in kg × 10 to 15 mg.
Child daily maximum: Weight in kg × 75 mg, capped at 4000 mg.
Adult single dose: Choose 500 mg, 650 mg, or 1000 mg, then stay below the daily cap.
Liquid volume: Dose in mg ÷ (mg per 5 mL ÷ 5).
Tablet count: Dose in mg ÷ tablet strength in mg.
Safe daily frequency: The lower result from clock spacing and maximum daily limit.
How to use this calculator
- Enter age and body weight carefully. For infants, use decimal years.
- Select whether you want liquid, tablet, or both calculations.
- Enter the product strength exactly as shown on the bottle or pack.
- Choose the spacing between doses and the first planned dose time.
- Tick any caution boxes that apply, then submit the form.
- Read the result section above the form, review warnings, and avoid exceeding the daily ceiling.
FAQs
1. Is this calculator a prescription tool?
No. It is an educational estimator for common oral paracetamol products. Individual diagnosis, dehydration, liver problems, very young infants, and overdose questions still need professional advice.
2. Why does weight matter so much for children?
Children are usually dosed by body weight rather than adult tablet habits. That helps prevent underdosing and reduces the risk of accidental overdose.
3. Why does the tablet estimate sometimes show fractions?
A weight-based dose may not match the available tablet size. When that happens, liquid formulations are often easier to measure accurately than splitting tablets.
4. Can I combine two paracetamol products?
Not unless you confirm the combined total carefully. Many cold, flu, and pain products already contain acetaminophen or paracetamol, which can silently push the daily amount too high.
5. What if the patient has liver disease or drinks heavily?
Use a clinician or pharmacist before relying on the estimate. Liver disease and regular heavy alcohol use can lower the safe limit.
6. Can I use this for a baby under 2 months old?
No. Very young infants need clinician-guided dosing because age, weight, and product type matter more, and label-style public instructions are not enough.
7. Does the chart replace the package label?
No. Always compare the result with the product label and any local clinician advice. Bottle concentrations and instructions vary by country and brand.
8. When should I get urgent help?
Get urgent help after an overdose, an uncertain amount, repeated vomiting, confusion, severe sleepiness, or if another acetaminophen product may also have been taken.