About This Calculator
Author
Malcolm A. Holliday and William E. Segar
First Published
1957
Evidence
Standard of care
Category
Critical Care
Original Study
The maintenance need for water in parenteral fluid therapy (Pediatrics, 1957)
About
The 4-2-1 rule estimates hourly maintenance fluid needs: 4 mL/kg for first 10 kg, 2 mL/kg for next 10 kg, 1 mL/kg for each additional kg.
Clinical Use
Maintenance fluid prescribing. Adjust for fever, losses, and clinical status.
