To determine intravenous fluid rate in ml/hr:

Use 4 ml/kg/hr for the first 10 kg, 2mg/kg/hr for the second 10 kg, and 1 ml/kg/hr for any weight over 20 kg.

So, for a 25 kg child: 4 x 10 + 2 x 10 + 1 x 5 = 65 ml/hr