Holliday-Segar hourly maintenance: 4 mL/kg/h for the first 10 kg, 2 mL/kg/h for the next 10 kg, 1 mL/kg/h for each kg above 20.
kg
Maintenance rate
110 mL/h
Formula
4 * min(weight, 10) + 2 * min(max(weight - 10, 0), 10) + max(weight - 20, 0)
Notes
Use isotonic fluid with glucose in children. In sick adults this overestimates needs (25-30 mL/kg/day is usual; 70 kg ≈ 75-90 mL/h) and enteral feeds and drug diluents count. Fluid-restrict in SIADH, cardiac/renal failure, raised ICP.References
Used in
Calculators support, not replace, clinical judgement. Check inputs and units, and confirm doses with your unit protocol.