Percentage vs Percentile
A percentage describes a part of 100. A percentile describes standing in a group. Scoring 90% on a test means you earned 90 marks out of 100. Scoring in the 90th percentile means you did as well as or better than 90% of the people who took the same test.
Percentage is a part of a whole
You only need two numbers that belong to the same scale: the part and the total. The result does not depend on anyone else. 87 marks out of 100 is 87%, whether you are the only student or one of a thousand.
percentage = (part / whole) × 100
Percentile is a rank in a group
A percentile needs a distribution. The 90th percentile is the value below which 90% of the observations fall. Two people can both score 90% and sit at very different percentiles if the test is unusually easy or unusually hard.
- 90% correct: you earned 90 out of 100 possible marks.
- 90th percentile: about 90% of the group scored at or below you.
- A 60% score can still be a high percentile on a difficult exam.
Which tool to use
This site calculates percentages, not percentile ranks from a data set. If you have marks obtained and total marks, use the marks calculator. If you have any part and whole, use what-percent. There is no percentile-to-percentage converter here because that conversion needs the full score list.
Related reading
Percentage and percentile questions
Only by coincidence. They use different inputs. One is your score over the total. The other is your position among other scores.
A percentile is reported with a percent-like number, but it is a rank, not a part of a whole. You cannot add two percentiles the way you add two percentage scores.
Divide marks obtained by total marks and multiply by 100. 42 out of 50 is 84%.
That conversion requires the full set of scores, not two numbers. The tools here stay on percentage arithmetic.
Use what-percent for any part and whole, or marks percentage when the labels are exam marks.