Klasifikasi IQ berdasarkan Skala Weschler
- 128 ke-atas : Very Superior
- 120-127 : Superior
- 111-119 : Bright Normal (High Average)
- 91-110 : Average
- 80-90 : Dul Normal (Low Average)
- 66-79 : Borderline-Defective
- 65 ke-bawah : Mentally Defective
Klasifikasi IQ berdasarkan Skala Stanford-Binet
- 140-169 : Very Superior
- 120-139 : Superior
- 110-119 : Bright Normal (High Average)
- 90-109 : Average (Rata-Rata)
- 80-89 : Dul Normal (Low Average)
- 70-79 : Borderline-Defective
David Weschler. The Measurement of Adult Intelligence, 3rd Ed. Baltimore: The Williams & Wilkins, 1944, p 190. Lewis M. Terman & Maud A. Merrill.
Stanford-Binet Intelligence-Scale. manual for The Third Revision Form L-M. Boston: Houghton-Mifflin, 1973, p 18. American Psychiatric Association. Diagnostic and Statistical Manual (DSM). 2nd Ed. Washington, D.C. APA, 1968, p 14.