Dosing by Weight
Educational only — verify before every dose
These tables reflect the standard amounts printed on over-the-counter packaging for two common fever and pain medicines. They are for reference when original packaging is lost. Every dose must be verified against the actual product label or a pharmacist/doctor — formulations and concentrations vary by brand and country. When in doubt, dose low or ask.
At a glance
- Dose by weight, never by age, whenever you know the weight.
- Only one medicine per ingredient — cold remedies secretly contain acetaminophen.
- Use the measuring device from the box — kitchen spoons vary by 2–3×.
- Write down time and amount; no aspirin under 19 with viral illness (Reye's syndrome).
- Educational only — verify every dose against packaging/professional advice.
The five rules
- Dose by weight, never by age, whenever you know the weight.
- Use only one medicine containing each ingredient. Many cold remedies secretly contain acetaminophen — double dosing is the most common overdose there is.
- Use the measuring device meant for it: the cup or syringe from the box, or a kitchen syringe — never kitchen spoons, which vary by 2–3×.
- Write down time and amount of every dose when several people share caregiving.
- No aspirin under 19 during viral illness — risk of Reye's syndrome.
Acetaminophen (Tylenol/paracetamol)
Liquid children's strength 160 mg per 5 mL. Dose every 4–6 hours, maximum 5 doses in 24 hours.
| Weight | Liquid (160 mg / 5 mL) |
|---|---|
| Under 12 lb / 5 kg | Ask a professional — do not guess |
| 12–17 lb / 5–7 kg | 2.5 mL |
| 18–23 lb / 8–10 kg | 3.75 mL |
| 24–35 lb / 11–15 kg | 5 mL |
| 36–47 lb / 16–21 kg | 7.5 mL |
| 48–59 lb / 22–26 kg | 10 mL |
| 60–71 lb / 27–32 kg | 12.5 mL |
| 72–95 lb / 33–43 kg | 15 mL |
| 96 lb+ / 44 kg+ | 20 mL, or 1–2 regular-strength tablets (325 mg each) |
Ibuprofen (Advil/Motrin)
Liquid infants'/children's strength 100 mg per 5 mL. Ages 6 months and up only. Dose every 6–8 hours, maximum 4 doses in 24 hours. Give with food if possible.
| Weight | Liquid (100 mg / 5 mL) |
|---|---|
| Under 6 months old | Not without professional direction |
| Under 12 lb / 5 kg | Ask a professional — do not guess |
| 12–17 lb / 5–7 kg | 2.5 mL |
| 18–23 lb / 8–10 kg | 3.75 mL |
| 24–35 lb / 11–15 kg | 5 mL |
| 36–47 lb / 16–21 kg | 7.5 mL |
| 48–59 lb / 22–26 kg | 10 mL |
| 60–71 lb / 27–32 kg | 12.5 mL |
| 72–95 lb / 33–43 kg | 15 mL |
| 96 lb+ / 44 kg+ | 20 mL, or 1 tablet (200 mg) |
Which one, when?
Either handles fever and pain. Ibuprofen also calms swelling (sprains, sunburn) but needs kidneys and hydration working well — with vomiting, diarrhea, or dehydration, acetaminophen is the safer pick. Do not alternate them unless directed professionally; alternation is where record-keeping errors become overdoses.
Adults without scales
Standard adult doses printed on packaging apply to anyone roughly 96 lb (44 kg) or more: acetaminophen 325–650 mg per dose, ibuprofen 200–400 mg per dose, taken with the frequency limits above.
Educational only — verify against packaging and professional advice before any dose. Tables mirror standard US OTC label amounts (FDA-published); concentrations differ outside the US.