Cognitive Test Scaled Score Calculator

Work out cognitive test scaled score instantly with clear inputs, formula shown and shareable results.

About Cognitive Test Scaled Score Calculator

Wechsler subtest scaled scores use a mean of 10 and standard deviation of 3, so scaled = 10 + 3z against age-group norms. A raw score of 34 where the age group averages 28 with SD 5 gives z = 1.2 and a scaled score of 13.6 - above average, at the 88.5th percentile. Age norming is essential because raw ability changes with development.

Formulas

Scaled score

scaled = 10 + 3 x z, using age-group norms

Interpretation bands

8-12 average, 13-15 above average, 16+ very superior

Worked example

With the default values below, Cognitive Test Scaled Score Calculator returns Scaled Score of 13.60. Change any input above and every figure here is recalculated in your browser.

Inputs used

Raw subtest scoreminimum 0: 34
Age-group mean raw score: 28
Age-group standard deviationminimum 0: 5

Results

Scaled Score: 13.60 /19
Underlying z Score: 1.2000
Percentile Rank: 88.49%
Qualitative Descriptor: Above average

Step by step

1Values used
2Scaled score
3Interpretation bands
4Scaled Score= 13.60 /19
5Underlying z Score= 1.2000
6Percentile Rank= 88.49
7Qualitative Descriptor= Above average

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Why norm by age group?

Because raw cognitive performance changes sharply with age. A ten year old's raw score means something different from an adult's.

Why is the scale capped at 19?

Because 19 is three standard deviations above the mean, beyond which the norming sample contains too few cases to differentiate reliably.