If you are told you are "in the 60th percentile" for something, it means 60% of the group are below you and 40% are at your level or above. That's all. It is a position in a queue, not a mark out of 100.
Line everyone up
Picture everyone in a group standing in a line, ordered from the smallest value to the largest: shortest to tallest, or lowest pay to highest. Your percentile is roughly how far along the line you are standing. Halfway along is the 50th percentile, which is the median. Nine-tenths of the way is the 90th.
A made-up example: in a running club of 200 people, your 5 km time beats 150 of them. You are faster than 75% of the club, so your time is at the 75th percentile for speed.
Join a club of elite athletes instead and the same time might put you in the 5th percentile. Your time didn't change; the group did.
That second point matters most. A percentile only means something alongside the group it was measured against. "Higher than 60% of employees aged 30 to 39" is a different claim from "higher than 60% of everyone".
It is not a score
The 90th percentile is not "90% good". Being above 90% of people on household electricity use is not an achievement, and being in the 20th percentile for working hours is not a failure. A percentile describes where you are, not how well you are doing.
Percentiles also bunch up in the middle. Most people are near the median, so a small change in your value can move you many percentile points there, while at the extremes a big change might move you only one or two.
How we work out your position
Statistics offices don't publish everyone's individual answers, for good privacy reasons. They publish summaries: the values at certain percentiles, or how many people fall into each band. We work from those.
- Between two published percentiles, we draw a straight line. If 40% earn under €35,000 and 50% under €40,000, then €37,500 is placed at about 45%.
- Inside a band, we assume people are spread evenly. If 1,000 people work 30 to 39 hours, we treat about 100 of them as working each hour in that range.
- Beyond the last published point, or in an open band such as "85 and over", we only say "at least" or "more than", because the data doesn't say how far the top end stretches.
Each answer on AboutAverage says which of these applied, so you know how exact it is. The figures you type are used in your browser to do this sum and are never sent to us.
What a percentile can't tell you
It can't tell you why you are where you are, or whether that is good. It also depends on the year: if everyone's pay rises and yours doesn't, your percentile falls even though your pay is unchanged. Read it as "where I stood in this group, at that time", and it is one of the most honest comparisons there is.