Paracetamol Dosage Calculator
Calculate safe paracetamol (acetaminophen) doses for children and adults by weight, age, and medication form.
Enter weight, age, and select the medication form to instantly get the correct paracetamol dosage in mg, ml, or tablet count.
Paracetamol Dosage Calculator
Calculate safe paracetamol (acetaminophen) doses for children and adults by weight, age, and medication form.
Click any example to load it into the calculator.
About the Paracetamol Dosage Calculator
Paracetamol (acetaminophen) is one of the most widely used analgesic and antipyretic medications in the world, prescribed for pain relief and fever reduction in both children and adults. Despite its wide availability as an over-the-counter medication, accurate dosing is critically important. Underdosing leads to inadequate symptom control, while overdosing — even unintentionally — can cause serious liver damage. This calculator is designed to help healthcare professionals, parents, and caregivers determine the appropriate dose based on the patient's weight, age, and the specific formulation available.
The fundamental principle of paracetamol dosing is weight-based calculation rather than age-based estimation. The standard recommended dose is 10–15 mg per kilogram of body weight per dose, with 15 mg/kg being the typical target for effective pain and fever management. This approach ensures that smaller children receive doses proportionate to their physiology rather than arbitrary age brackets that can lead to under- or over-treatment.
Paracetamol is available in numerous formulations, including oral suspensions (liquids), standard tablets, effervescent tablets, suppositories, and intravenous preparations. For children, oral suspensions are the most common form because they allow precise dose measurement. The calculator supports liquid and tablet forms, which together cover the vast majority of home and clinical use cases worldwide.
For liquid formulations, the key variable is the concentration expressed in mg/ml. Common pediatric suspensions include 160 mg/5ml (32 mg/ml), 120 mg/5ml (24 mg/ml), and 250 mg/5ml (50 mg/ml). Knowing the exact concentration is essential: confusing different concentrations is one of the most common medication errors. The calculator converts the calculated milligram dose into a volume in milliliters, making it straightforward to measure with an oral syringe or dosing cup.
For tablets, the calculation provides the number of tablets (or fraction thereof) required for a single dose. Standard adult tablet strengths are typically 500 mg or 325 mg. The calculator also computes the maximum recommended daily dose, which is 4,000 mg for adults (often reduced to 3,000 mg for older adults and those with liver concerns) and approximately 75 mg/kg for children, not to exceed the adult maximum.
The dose interval is another critical factor. Paracetamol should generally not be taken more frequently than every four hours, and most regimens recommend every six hours (four times daily) to maintain a safe safety margin and avoid accumulation. Respecting the interval between doses is as important as the dose size itself in preventing toxicity.
This tool is intended for educational and reference purposes and does not replace individualized medical advice. Always check the medication label for specific dosing instructions, use a calibrated measuring device for liquids, and consult a healthcare provider when in doubt.
Paracetamol Dosage Examples
| Patient & Form | Single Dose | Notes |
|---|---|---|
| Child, 20 kg, 32 mg/ml liquid | 300 mg / 9.38 ml | 15 mg/kg × 20 kg = 300 mg; 300 ÷ 32 = 9.38 ml per dose, 4 times daily. |
| Child, 30 kg, 500 mg tablet | 450 mg / 0.9 tablets | 15 mg/kg × 30 kg = 450 mg; 450 ÷ 500 = 0.9 tablets per dose, 3 times daily. |
| Adult, 70 kg, 500 mg tablet | 1000 mg / 2 tablets | Max single dose 1000 mg; 1000 ÷ 500 = 2 tablets per dose, 4 times daily. |
| Adult, 80 kg, 500 mg tablet | 1000 mg / 2 tablets | 15 mg/kg × 80 kg = 1200 mg, capped at 1000 mg; 2 tablets per dose, 4 times daily. |
How to Use the Paracetamol Dosage Calculator
- Enter the patient's accurate weight in kilograms. Weight is the most important factor for correct dosing.
- Optionally enter the patient's age in years for reference. The dosage (mg/kg) field defaults to 15 mg/kg — adjust if your clinical protocol recommends a different value.
- Select the medication form: Liquid or Tablet. For liquid, enter the concentration in mg/ml (check the bottle label). For tablets, enter the tablet strength in mg.
- Enter the number of doses per day (typically 3–4) and the interval between doses (typically 4–6 hours). The calculator shows the maximum recommended daily dose automatically.
- Click 'Calculate Dosage' to see the single dose in mg, the volume in ml or tablet count, and the maximum daily dose. Always verify the result against the medication packaging and consult a healthcare professional if unsure.
Frequently Asked Questions
What is the standard paracetamol dose per kg?
The standard recommended dose is 10–15 mg/kg per dose. Most protocols use 15 mg/kg for effective fever and pain relief in children and adults. The maximum single dose for adults is capped at 1,000 mg regardless of weight.
How often can I give paracetamol?
Paracetamol can be given every 4 to 6 hours as needed, but no more than 4 doses in a 24-hour period. Always respect the minimum interval between doses to avoid accumulation and potential toxicity.
What is the maximum daily dose of paracetamol for adults?
For healthy adults, the maximum daily dose is 4,000 mg (4 g). For older adults, people with liver disease, or regular alcohol users, it is generally recommended to limit intake to 2,000–3,000 mg per day. Always follow the prescriber's guidance.
How do I calculate paracetamol volume from a liquid suspension?
Divide the required dose in milligrams by the concentration of the suspension in mg/ml. For example, if a child needs 300 mg and the suspension is 32 mg/ml (160 mg/5ml), the volume is 300 ÷ 32 = 9.38 ml. Always use an oral syringe to measure accurately.
Is paracetamol safe for children?
Yes, paracetamol is generally considered safe for children when used at the correct weight-based dose and appropriate intervals. Underdosing is ineffective and overdosing risks liver damage. Always use the correct formulation for the child's age and weight, and never exceed the maximum daily dose.
Can I use paracetamol if I already take other medications?
Many combination cold and flu products already contain paracetamol. Always check all medications you are taking to avoid accidental double-dosing. If in doubt, speak with a pharmacist or physician before taking additional paracetamol.