paracetamol overdose calculator

Paracetamol Safety Check Calculator

This tool gives a rapid screening estimate for possible paracetamol (acetaminophen) toxicity. It is not a diagnosis. If you are worried, contact emergency care or poison services now.

Or calculate from tablets/liquid units:

Emergency signs: confusion, severe vomiting, extreme sleepiness, seizures, breathing problems, collapse, or if a child may have taken a toxic amount. Call emergency services immediately.

What this calculator is for

Paracetamol overdose can quietly injure the liver, and serious symptoms may be delayed. People often feel “okay” early on, which is why a fast dose-based check can be useful while arranging professional advice.

This page helps you estimate dose in mg/kg and flags when urgent emergency assessment is recommended.

How the estimate works

1) Total amount taken

The calculator uses either:

  • a direct total dose you type in (mg), or
  • tablet strength × number of tablets/units.

2) Dose by body weight (mg/kg)

A person’s risk is partly related to body size, so total dose is divided by body weight.

3) Red-flag context

Modified-release preparations, repeated doses over time, uncertain history, or intentional ingestion all increase risk and require in-person assessment.

Reference risk bands used in this tool

Estimated exposure How this tool labels it Suggested action
≥150 mg/kg or ≥7.5 g (single acute ingestion) Potentially toxic / high risk Go to emergency care now and call poison services.
≥200 mg/kg or ≥10 g Very high risk Emergency department immediately.
75–149 mg/kg or 4–7.49 g Concerning Urgent same-day poison center/medical review.
<75 mg/kg and under common adult limits Lower immediate risk Still verify with poison center; avoid further dosing.

Thresholds vary by country and clinical context. Hospitals may use blood tests and treatment protocols that this calculator cannot replace.

What to do right now if overdose is possible

  • Do not wait for symptoms. Seek medical advice immediately.
  • Bring the medication packaging (strength/formulation) if possible.
  • Do not take more paracetamol while awaiting guidance.
  • If intentional self-harm is involved, call emergency services now.

Important special situations

Modified-release products

These can delay and prolong absorption. Even seemingly modest doses can require longer monitoring and different treatment decisions.

Repeated extra dosing over 24+ hours

Staggered or repeated supratherapeutic use can be dangerous even if no single dose appears massive. Clinical review is needed.

Higher baseline risk

Liver disease, chronic heavy alcohol use, prolonged fasting, and interacting medicines may lower safety margins.

Frequently asked questions

Is there a “safe” maximum daily dose?

For many adults, product labeling often sets 4,000 mg/day as an upper limit, but many clinicians recommend lower routine totals (such as 3,000 mg/day) depending on patient factors.

Can symptoms be delayed?

Yes. Early symptoms may be mild or absent. Delayed liver injury is the main concern.

Should I induce vomiting at home?

No. Do not induce vomiting unless explicitly told by professionals.

Bottom line

Use this calculator as a quick triage aid only. If there is any doubt, contact poison services or emergency care now. Fast treatment can be lifesaving.

🔗 Related Calculators