As a rule of thumb:
Children aged 1-3 years = 1 litre
Children aged 4-8 years = 1.2 litres
Children aged 9 years and over = 1.5 litres
Your child should drink mainly water.
For infants weighing between 3.5 kg to 10 kg, the daily fluid requirement is 100 ml/kg.
For children 11 kg to 20 kg, the daily water requirement is 100 ml/kg for the first 10 kg and 50 ml/kg for every kg above 10 kg.
For children above 20 kg, the fluid requirement is calculated as 1500ml for 20 kg and 20 ml/kg for every kg above 20 kg, but more than 2400ml of fluid should not be administered at once.
Here is a good online calculator for daily fluid requirements.