How Can I Find Out if My Child is Overweight or Underweight? (BOYS)
Method:
 Measure your child's weight (in kg) and height (in cm);
 Find the height closest to your child's height from the height column;
 Check the reference weights for 'overweight' and 'underweight' across the same row;
 Compare your child's weight with the reference weights.
BOYS 
Body Weight (kg) Below the reference weight 
Body Weight (kg) Above the reference weight 
BOYS 


Child’s Height (cm) 
Underweight 
Overweight 
Child’s Height (cm) 

75 
7.5 
11.3 
75 

77 
7.9 
11.8 
77 

79 
8.2 
12.3 
79 

81 
8.6 
12.9 
81 

83 
8.9 
13.4 
83 

85 
9.3 
13.9 
85 

87 
9.6 
14.4 
87 

89 
10.0 
15.0 
89 

91 
10.3 
15.5 
91 

93 
10.7 
16.1 
93 

95 
11.1 
16.6 
95 

97 
11.5 
17.2 
97 

99 
11.9 
17.8 
99 

101 
12.3 
18.4 
101 

103 
12.7 
19.1 
103 

105 
13.2 
19.7 
105 

107 
13.6 
20.4 
107 

109 
14.1 
21.2 
109 

111 
14.6 
21.9 
111 

113 
15.2 
22.8 
113 

115 
15.7 
23.6 
115 

117 
16.3 
24.5 
117 

119 
17.0 
25.5 
119 

121 
17.6 
26.5 
121 

123 
18.4 
27.5 
123 

125 
19.1 
28.6 
125 

127 
19.9 
29.8 
127 

129 
20.7 
31 
129 

131 
21.6 
32.3 
131 
Example:
 A boy measures 91cm in height and 13.5kg in weight.
 Find 91cm on the "Child's Height" column.
 Find the reference weights on the same row. For a boy of 91 cm tall, having a body weight less than 10.3 kg is underweight, more than 15.5 kg is overweight.
 Since the boy weighs 13.5 kg, he is of normal weight.
Source of information: Leung SSF, Lau JTF, Tse LY, Oppenheimer SJ.
Weightforage and weightforheight reference for Hong Kong children from
birth to 18 years. J Paediatr. Child Health 1996:32.103109
Underweight is defined as having a weight below 80% median weight for height,
overweight is having a body weight above 120% median weight for height