Percentile vs Percentage: Not the Same Thing

The distinction

• Percentage — what portion of a whole. “You scored 85% on the test” means you got 85 of 100 possible points.
• Percentile — your rank among others. “You scored in the 85th percentile” means you scored higher than 85% of test-takers.

The same student can have an 85% test score and a 95th percentile rank — those numbers describe different things.

Why this matters in standardized tests

SAT, GRE, GMAT, MCAT — all report both raw scores and percentiles. A 700 on the SAT Math is a percentile rank: roughly 92nd percentile (better than 92% of test takers). The 700 itself is not a percentage of correct answers.

Common percentiles in growth charts

Pediatricians plot children’s height and weight on percentile charts. A child in the “50th percentile” for weight is right at the median for their age — taller than half, shorter than half. A child at the “95th percentile” is taller than 95% of peers — well above average.

Why percentile is symmetric in a way percentage isn’t

Two students with 85% scores got the same number of points. Two students at the 85th percentile got the same rank — even if one took an easier version of the test and got more points. Percentile normalizes for difficulty.

Percentile calculation

percentile = (number of values below you ÷ total values) × 100

If you scored higher than 47 of 50 students, your percentile is 47 ÷ 50 × 100 = 94. You’re in the 94th percentile.

Quartiles, quintiles, deciles

• Quartiles: 25th, 50th, 75th percentiles (divide data into 4)
• Quintiles: 20th, 40th, 60th, 80th (divide into 5)
• Deciles: 10th, 20th, 30th... 90th (divide into 10)

These are all special cases of percentiles — they just specify particular cut points.