How your BrainTally score is calculated

Most online tests hand you a number and leave you to guess what it means. Some go further and wrap it in the language of science: a percentile, a bell curve, a comparison with "the population". We decided early on that BrainTally would do something less impressive-sounding and more useful. We would tell you exactly how your score was counted, in words you can check on your fingers.

This post walks through that calculation from the first answer to the number on the dial, and explains the two things we deliberately don't claim.

Step 1: every answer is right or wrong

Each question in the scored test is worth one point if you answer it correctly and nothing if you don't. There is no partial credit, and there is no negative marking: a wrong answer costs you nothing more than an unanswered one. That has a practical consequence worth knowing before you start. Never leave a question blank. A guess can only help.

Unanswered questions count as wrong. That's also why a test that runs out of time, or that you hand in early, usually scores lower than a complete one, and why your results page tells you when that happened.

Step 2: all your answers go into one pot

Your results page shows how you did in each category, such as verbal, logical, spatial and numerical reasoning, with a bar for each. Those bars are there to help you see your strengths. They don't feed the total separately. Every question goes into one pot, and your raw score is simply the number you got right out of the number you were asked.

One honest footnote: because the pot is shared, a category with more questions has more influence on your overall score than a category with fewer. We print that on the results page too, because a weighting that's real but hidden is still a weighting.

Step 3: the percentage, rounded once

Your raw score becomes a percentage, rounded to a whole number. If you answered 9 of 12 correctly, that's 75%. We round once, at this step, and use that same figure everywhere afterwards. It sounds like a tiny detail, but it means the arithmetic on your results page always adds up, line by line.

Step 4: add 50

Here is the whole scale, in one sentence: your score is your percentage correct plus 50.

So 75% correct gives a score of 125. Half the questions right, 50%, gives exactly 100. That's why 100 is described on your results page as this assessment's midpoint.

The number is kept between 55 and 145, so the dial has fixed ends. In practice that means anything from 95% to 100% correct shows as 145, and anything from 0% to 5% shows as 55.

What the bands mean

Alongside the number, you'll see one short line that places it on the scale:

• 130 and above: well above this assessment's midpoint
• 115 to 129: above the midpoint
• 86 to 114: around the midpoint
• 71 to 85: below the midpoint
• 70 and below: well below the midpoint

Notice the wording. We say midpoint, not average. That isn't pedantry.

What we don't claim: a percentile

A percentile ("you scored higher than 84% of people") only means something if the test has been given to a large, representative group of people under controlled conditions, and their results have been measured. That process is called norming. Our scale is not normed. The 100 in the middle is a point we chose, half the questions right, not the measured average of anybody.

So we don't print a percentile, and we never will on this scale. Many sites do exactly that with no reference group behind the number. It looks authoritative, and it isn't true.

What we don't claim: an IQ

For the same reason, a BrainTally score isn't an IQ score, even though both use 100 as a reference point. A real IQ test is administered by a trained professional, under standard conditions, and compared against a normed population. BrainTally is a short reasoning assessment you can take at home, for learning and for interest. It's a good way to see where you are strong, and to track how your own results change over time. It's not a clinical measurement, and it shouldn't be used to make medical, educational or employment decisions.

Why the correct answers aren't shown

People sometimes ask why the results page shows which questions you got wrong but not the right answers. Every attempt, retakes included, draws from the same question bank. Publishing the answers would make the next attempt meaningless, including yours. Everything else, how each question was counted and what each category added, is on the page.

See it for yourself

The quickest way to understand the method is to watch it work. Try a free sample of five questions with no sign-up, or take the scored test: your overall score, and the full working behind it, are always free to see.

Try 5 free questions

For the full details of the scale, see Understanding your score in the guide.