Average bih weight in India: 2.8 Kg (2.7-2.9 Kg) BW doubles at 5 months, triples by 1 year and quadraples by 2 years age So, BW of 3 Kg will become 6 Kg, 9 Kg and 12 Kg at 5 months, 1 year and 2 years age respectively. Weight gain Pattern in Children Age Weight increments 0-3 months 200 grams per week 4-6 months 150 grams per week 7-9 months 100 grams per week 10-12 months 50-75 grams per week 0-1 year 7 Kg per year 1-2 years 2.5 Kg per year 3-5 years 2.0 Kg per year Ref: Park 25th edition Pgno: 578