IQ to WAIS / WISC Score Converter

Convert IQ ↔ WAIS / WISC

How the conversion works

IQ and WAIS / WISC scores are normalised on bell-curve distributions. The conversion maps a person's standing in one distribution to the equivalent standing in the other.

• IQ: mean 100, standard deviation 15.
• WAIS and WISC families: all use mean 100, SD 15. Cross-walks between editions are nominally identity (IQ 100 = IQ 100), but in practice raw scores on older editions tend to inflate due to the Flynn effect. This converter applies a small Flynn-effect adjustment to map between editions: ≈ 3 IQ points per decade of separation between norming dates. The current edition (or "reference IQ" in this tool) is used as the calibration baseline.

IQ-equivalent = (target − mean_target) / SD_target × 15 + 100
target-equivalent = (IQ − 100) / 15 × SD_target + mean_target

Common IQ ↔ WAIS / WISC reference table

Important caveats

• Within a family (WAIS-IV ↔ WAIS-V, WISC-IV ↔ WISC-V), Pearson correlations on the same individual are typically 0.90-0.95. Across families (WAIS ↔ WISC), correlations on the same individual are slightly lower (0.85-0.90) because of age-based item targeting.
• Extreme-tail conversions are less reliable because both tests have fewer calibration cases there.
• No score entered here is stored, submitted, or connected to an account.

Related tools

IQ percentile calculator · IQ score chart · IQ to Z-score converter · Historical IQ Tests Archive