IQ percentile calculator
Map an IQ to a percentile and band on the SD 15 or SD 16 normal curve. Educational estimate — not a clinical Wechsler administration.
Defaults to your region. Switch to compare any other scale.
WAIS/WISC-style convention: mean 100, SD 15. Most modern IQ percentile charts use this.
Most adult Wechsler full-scale scores fall roughly 40–160.
Result
84.1%
Percentile
Higher than about 84.1% of people
- Qualitative bandHigh average (110–119)
- z-score1.00
- Scale SD (σ)15
- Assumed mean (μ)100
High average
Educational estimate from a normal curve (μ=100). Not a clinical assessment, not WAIS/WISC, and not a substitute for a licensed psychologist.
About this tool
An IQ percentile calculator maps a score onto a normal curve centered at 100. Choose Wechsler-style SD 15 or a Stanford–Binet-style SD 16, then read percentile, z-score, and a qualitative band.
Percentiles answer “what share of the reference population scores at or below this?” They are not a clinical WAIS or SB administration. Real tests use norm tables, confidence intervals, and trained interpretation.
Use the companion rarity tool when you want a 1-in-N framing for the upper tail. Keep wording educational — this site does not diagnose ability or giftedness.
Formula
z = (IQ − 100) / σpercentile = 100 × Φ(z) (standard normal CDF)σ = 15 (Wechsler) or 16 (Stanford–Binet / Cattell-style)
How it is calculated
- Enter your IQ score (typically 40–160 on modern scales).
- Choose Wechsler SD=15 (default) or SD=16.
- We compute z-score, CDF percentile, and a descriptive band.
- If your country, school or provider uses different rules, pick another option in the “Standard” menu at the top.
Questions
How is IQ percentile calculated?
Most published IQ scales are designed so scores are approximately normal with mean 100. We convert IQ to a z-score with your chosen SD, then use the standard normal CDF Φ(z) as the percentile.
Why SD 15 vs SD 16?
Wechsler batteries (WAIS, WISC) standardize to SD 15. Some Stanford–Binet editions and Cattell-style charts used SD 16. The same numeric IQ is slightly “rarer” on SD 16 because the tails are thinner for a given deviation from 100.
Is this a real IQ test or WAIS result?
No. This only converts a number you already have into a percentile under a normal model. It is not a clinical assessment and not WAIS/WISC.
What do the qualitative bands mean?
They echo common Wechsler verbal labels (e.g. average 90–109, high average 110–119, superior 120–129, very superior ≥130). Labels vary by manual and era; treat them as rough descriptors only.