The standard weight of a five-month-old baby is about 6kg, but there are individual differences. Newborns grow and develop faster in the first year, and their weight increases by about 0.6kg per month in the first half of the year, and 0.5kg per month in the second half of the year.For babies aged 1-6 months, the standard measurement formula for body weight can be calculated, i.e., birth weight (or 3kg) + age in months x 0.6kg.The calculation gives the standard weight for a five-month-old baby to be about 6kg or so. As the baby’s weight is affected by genetic and environmental factors, there is a large individual difference. However, if the child is noticeably thin compared with children of the same age and sex, or if the weighing reveals excessive deviation from the standard weight, it is noted that it should be necessary to take the child for a specific growth and development assessment.