The 4/2/1 rule:
- 4 ml/kg for first 10kg, 2ml/kg for the next 10kg, 1 ml/kg for every 1kg over 20.
- For example, for a 70kg person: 4×10=40; 2×10=20; 1×50=50. Total=110 ml/hr
This online calculator seems to use this rule.
http://www.mdcalc.com/maintenance-fluids-calculations/
It seems to work with both pediatric and adult patients. Check!