Follow your curiosity

What discovery has been shared with you?

FACTREE gives you something interesting to discover every day — and something worth talking about together.

Start with one fact. Explore it, go deeper, then follow whichever branch catches your imagination.

Choose subjects for a surprise

Exploring any topic

Begin your discovery

Your next discovery is one click away.

Choose one or more subjects above, or leave Any Topic selected and let curiosity decide.

Mathematics

Z-Score (Standard Score)

Quick fact

A z-score of 0 means the value is exactly average; a z-score of 2 means it's two standard deviations above the mean, placing it in the top 2.5% of a normal distribution (assuming normality).

Why this is interesting

Have you ever wondered how unusual your test score really is compared to the rest of the class? The z-score is the universal ruler that measures exactly that—turning any score into a simple, comparable number.