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Paracetamol Dose for Low-Weight Adults

Calculate a weight-adjusted paracetamol dose for adults under 50 kg or with liver risk factors.

By Dr Amer Sheikh, GP Updated 17 October 2026 Clinical review pending

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When to adjust the dose

Dosing

Consider 15 mg/kg per dose, every 4 to 6 hours, up to 4 doses in 24 hours. Standard adult dosing is 1 g up to four times daily, maximum 4 g.

Frequently asked questions

What is the paracetamol dose for someone under 50 kg?

Consider 15 mg/kg per dose, up to four times a day.

Why reduce paracetamol in low weight?

To reduce the risk of liver toxicity.

What if the dose falls between tablet sizes?

Use the nearest dose not above the calculated dose, or a liquid.

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References

  1. MHRA. Paracetamol: dose adjustment for adults with low body weight. Drug Safety Update.
  2. BNF. Paracetamol. bnf.nice.org.uk

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