Maintenance Fluids
Hourly and daily maintenance fluid requirements by weight. The result updates as you type.
Method
Hourly (4-2-1): 4 mL/kg for the first 10 kg + 2 mL/kg for the next 10 kg + 1 mL/kg for each kg above 20
Daily (100-50-20): 100 mL/kg for the first 10 kg + 50 mL/kg for the next 10 kg + 20 mL/kg for each kg above 20
Holliday and Segar derived these rates from the caloric expenditure of hospitalized children, assuming about 100 mL of water per 100 kcal expended. The hourly and daily rules give slightly different totals because 4-2-1 is a rounded hourly version of the daily rule.
The original rates were paired with hypotonic fluid. The 2018 American Academy of Pediatrics guideline recommends isotonic solutions with appropriate potassium and dextrose for most children 28 days to 18 years who need maintenance intravenous fluids, because hypotonic fluid raises the risk of hyponatremia. Postoperative children often need less than the calculated volume.
Sources: Holliday MA, Segar WE. The maintenance need for water in parenteral fluid therapy. Pediatrics. 1957;19(5):823–832. Find on PubMed. Feld LG, Neuspiel DR, Foster BA, et al. Clinical practice guideline: maintenance intravenous fluids in children. Pediatrics. 2018;142(6):e20183083. Find on PubMed.