Ask "what does this job pay?" and most of us answer with a single number. But pay is not one number — it is a distribution. Inside the same job title sit fresh hires and ten-year veterans, capital-region and provincial workers, large firms and small ones, all lined up together. How you read that line decides where "typical" actually lands. And the most honest tool for reading it is the percentile.
What is a percentile — p50, p90, p10
Percentiles are simpler than they sound. Picture 100 people in a given job lined up from the lowest paid on the left to the highest paid on the right.
- p50 (the median) — the person standing exactly in the middle, the 50th. Half earn less, half earn more. This is the value closest to "typical."
- p90 (top 10%) — the 90th person from the left. This is the point that phrases like "the top 10% in this job earn this much" actually refer to.
- p10 (bottom 10%) — the 10th person, where new hires, part-time, and shorter-hours roles tend to cluster.
So a percentile tells you "which spot in the line you stand at." If your pay is at p70, you are roughly the 70th of 100 people in the same job. That is far richer information than a single average point.
Why the average keeps getting inflated
The mean adds up everyone's pay and divides by the head count. Intuitive, but it has one fatal weakness: it gets dragged hard by a handful of extreme values.
Here is a simple example. Say a small team has nine people each earning 30M won. Then one executive earning 300M won joins. The team's mean becomes (30M times 9 plus 300M) divided by 10, or about 57M won. Yet the person in the middle — the median (p50) — is still 30M won. Look only at the mean and you would assume "this team earns around 57M," when in reality nine of the ten earn 30M.
Pay distributions almost always have this long right tail. The bottom is fenced in — pay cannot drop below zero — while the top is open all the way to hundreds of millions. So the mean always sits above the median and inflates where the "ordinary person" really stands. When an article highlights only the "average salary," it is worth a moment of healthy suspicion.
How to read "top 10% salary"
News and forums often say things like "the top 10% in this job clear 100M won." That is really pointing at the single p90 value — and the phrase carries two traps.
- p90 is not "the average of the top 10%"; it is just the value at the 90th spot. Even within the top 10%, the 91st and the 99th person differ enormously. Averaging the whole top tenth gives a figure well above p90.
- You must check what population it describes. "Top 10% of all workers," "top 10% of this job," and "top 10% of one company" make the very same 100M won mean entirely different things.
So when reading percentiles, always ask three things together: which job, which experience band, and which region or company size. The same "p90" means something completely different for a nationwide average that includes new grads versus a seven-year veteran at a capital-region large firm. The moment you drop the conditions and compare bare numbers, you are weighing apples against oranges.
A sense of distribution is a sense of price
What is interesting is that this percentile instinct is not limited to salaries. Home prices, used cars, stock trading volume, city-by-city cost of living — almost every price in the world has a skewed distribution. The reason "average home price" differs from "the home an ordinary person buys" is identical: a few ultra-high sales drag the mean upward.
So people who estimate prices well hold not a single point in their heads but the shape of the distribution: a sense of "this is roughly the middle, it opens up this far above, and it is fenced in below." That is a sense of distribution, and a sense of distribution is a sense of price. This is exactly what the PriceGuess salary quiz aims at — missing a couple of guesses and feeling, in your gut, "my mental average was puffed up too high."
Wrap-up
When you meet a pay figure, read it in this order. First, is it a mean or a median? Second, which way is the distribution skewed? Third, are there percentiles like p90 and p10? Fourth, are job, experience, and region attached? Just those four checks let you read the same article in far more dimensions.
This article is educational and is not a recommendation to buy, sell, or hold any asset; figures reflect public records at publish time.
