IQ Score Estimate Calculator

Work out iq score estimate instantly with clear inputs, formula shown and shareable results.

About IQ Score Estimate Calculator

The raw score is standardised into a z-score, then mapped onto the IQ scale which is defined as mean 100 and standard deviation 15. IQ is a rank within a norm group rather than an absolute measure, so the figure is only meaningful if the mean and standard deviation come from a properly normed sample.

Formulas

Z-score

z = (raw score - norm mean) / norm standard deviation

IQ scale

IQ = 100 + 15 x z

Worked example

With the default values below, IQ Score Estimate Calculator returns Estimated IQ score of 115.0. Change any input above and every figure here is recalculated in your browser.

Inputs used

Your raw scoreminimum 0: 48
Mean raw score for the norm groupminimum 0.1: 40
Standard deviation of raw scoresminimum 0.1: 8

Results

Estimated IQ score: 115.0
Percentile in the norm group: 84.13%
Z-score: 1.0000
Rarity: About 1 in 6.3 score higher

Step by step

1Values used
2Z-score
3IQ scale
4Estimated IQ score= 115.0
5Percentile in the norm group= 84.13
6Z-score= 1.0000
7Rarity= About 1 in 6.3 score higher

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.
This converts a raw score onto the IQ scale using norms you supply. It is not a validated intelligence test.

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

This converts a raw score onto the IQ scale using norms you supply. It is not a validated intelligence test.

Frequently Asked Questions

How is the IQ Score Estimate figure worked out?

z = (raw score - norm mean) / norm standard deviation. The raw score is standardised into a z-score, then mapped onto the IQ scale which is defined as mean 100 and standard deviation 15.

Why does this matter?

IQ is a rank within a norm group rather than an absolute measure, so the figure is only meaningful if the mean and standard deviation come from a properly normed sample.

What do I need to enter?

Enter your raw score, mean raw score for the norm group, standard deviation of raw scores. The defaults shown are a realistic worked example — swap in your own figures to get a result you can use.