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 − meantarget) / SDtarget × 15 + 100
target-equivalent = (IQ − 100) / 15 × SDtarget + meantarget
Common IQ ↔ WAIS / WISC reference table
| IQ | WAIS / WISC | Percentile |
|---|---|---|
| 100 | WAIS-IV ~102, WAIS-III ~105 | ~50th (current) |
| 115 | WAIS-IV ~117, WAIS-III ~120 | ~84th (current) |
| 130 | WAIS-IV ~132, WAIS-III ~135 | ~98th (current) |
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
Cite this converter
Editorial content and curation are released under CC BY-SA 4.0. This converter is part of the What's Your IQ educational resources.