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Pediatric IV fluid calculator

Maintenance (Holliday–Segar / 4-2-1), fluid restriction, crystalloid bolus, dehydration deficit and WHO Plan C — for wards, emergency rooms and clinics.

Holliday–Segar maintenance (4-2-1 rule)

  • First 10 kg: 100 mL/kg/day (4 mL/kg/h)
  • Next 10 kg: 50 mL/kg/day (2 mL/kg/h)
  • Each kg above 20 kg: 20 mL/kg/day (1 mL/kg/h)

Use isotonic fluids and check electrolytes and glucose at least daily. Children with pneumonia, meningitis, bronchiolitis or after surgery often need 50–80% of maintenance.

Bolus and deficit

Give 10–20 mL/kg of isotonic crystalloid for shock and reassess after each bolus. In severe malnutrition use 15 mL/kg over an hour, and without intensive-care support avoid boluses in febrile children who are not hypotensive (FEAST trial). Deficit (mL) ≈ % dehydration × weight (kg) × 10, replaced alongside maintenance.

Frequently asked questions

How is pediatric maintenance fluid calculated?

100 mL/kg/day for the first 10 kg, 50 mL/kg/day for the next 10 kg and 20 mL/kg/day for each kg above 20 kg (Holliday–Segar). The hourly 4-2-1 rule gives the same volume: 4 mL/kg/h, 2 mL/kg/h and 1 mL/kg/h.

Which fluid should be used for maintenance?

Isotonic fluid — 0.9% sodium chloride with 5% dextrose or a balanced crystalloid — to reduce the risk of hyponatraemia (AAP 2018, NICE NG29). Restrict volume in children at risk of fluid overload or SIADH.

What is WHO Plan C?

For severe dehydration: 100 mL/kg of Ringer’s lactate (or 0.9% saline). Infants under 12 months get 30 mL/kg in 1 hour then 70 mL/kg over 5 hours; older children 30 mL/kg in 30 minutes then 70 mL/kg over 2½ hours. Not for severe acute malnutrition.

Sources

  1. Holliday MA, Segar WE. The maintenance need for water in parenteral fluid therapy. Pediatrics 1957.
  2. Feld LG et al. Clinical practice guideline: maintenance intravenous fluids in children. Pediatrics 2018 (AAP)
  3. NICE NG29: Intravenous fluid therapy in children and young people in hospital
  4. WHO: The treatment of diarrhoea (Plan C)
  5. Maitland K et al. Mortality after fluid bolus in African children with severe infection (FEAST). NEJM 2011