Depends upon the test, since there are a number of different IQ tests. The standard test used by Mensa uses the following scale adjusted for age. IQ also increases several points (5 to 9 points on average) between childhood and maturity.
1 - 19 Profound Mental Retardation
20 - 34 Severe Mental Retardation
35 - 49 Moderate Mental Retardation
50 - 69 Mild Mental Retardation
70 - 79 Borderline Mental Retardation
80 - 114 Average Intelligence (100 iq is baseline average)
115 -129 Bright
130 - 144 Moderately Gifted (Superior)
145 - 159 Highly Gifted
160 - 175 Exceptionally Gifted (Genius)
over 175 Profoundly Gifted
1 - 19 Profound Mental Retardation
20 - 34 Severe Mental Retardation
35 - 49 Moderate Mental Retardation
50 - 69 Mild Mental Retardation
70 - 79 Borderline Mental Retardation
80 - 114 Average Intelligence (100 iq is baseline average)
115 -129 Bright
130 - 144 Moderately Gifted (Superior)
145 - 159 Highly Gifted
160 - 175 Exceptionally Gifted (Genius)
over 175 Profoundly Gifted