IQ Score Calculator

1. Select your test type. If you took the WAIS-IV, WISC-V, or Raven's Matrices, select the matching preset. For other standardized tests, choose Custom and enter the test's mean and standard deviation.
2. Enter your raw score. This is the score you actually received on the test, not yet converted to an IQ scale. For the WAIS-IV and WISC-V, the raw composite score is already on the standard IQ scale (mean 100, SD 15), so enter it directly.
3. For Custom tests: enter the test mean and standard deviation. These are found in the test documentation or scoring report. For example, if your workplace used a test with a mean of 50 and SD of 10, and you scored 65, enter those values.
4. Read your standardized IQ score and percentile. The calculator converts your score to the standard IQ scale (mean 100, SD 15) and shows your percentile rank and classification.

Modern IQ scores are standardized scores, not raw test scores. The key insight is that any test score can be placed on the IQ scale by first computing a z-score (how many standard deviations above or below the mean the score is), then converting that z-score to the IQ scale.

Step 1: Compute the Z-Score

Z = (Raw Score – Test Mean) / Test Standard Deviation

Example: Raw score = 65, Test mean = 50, Test SD = 10
Z = (65 – 50) / 10 = 1.5

Step 2: Convert to IQ Scale

IQ = 100 + 15 × Z

Example: Z = 1.5
IQ = 100 + 15 × 1.5 = 100 + 22.5 = 123 (rounded to 123)

The IQ scale uses a mean of 100 and a standard deviation of 15 by convention. This means 68% of people score between 85 and 115 (within 1 SD of the mean), and 95% score between 70 and 130 (within 2 SD).

Step 3: Find the Percentile

Percentile = Normal CDF(Z) × 100

Z = 1.5 → Percentile ≈ 93.3rd
This means the person scored higher than 93.3% of the population.

A score of 130 (2 SD above mean) corresponds to the 97.7th percentile. Only about 2.3% of people score above 130. Mensa, the high-IQ society, accepts people who score at or above the 98th percentile, which corresponds to an IQ of approximately 131.