A Percentage Point Is Not the Same as a Percent
Percent means by the hundred. Confusing a rise of five percent with a rise of five percentage points is one of the commonest errors in reporting.
Percent means by the hundred, from Latin *per centum*. The trap is the difference between a percent and a percentage point. If a rate goes from 4 per cent to 5 per cent, that is a rise of one percentage point — but a rise of twenty-five per cent. Both are correct, and they sound very different in a headline.
- By the hundred. *Twenty percent of the total.*
- Percentage — a proportion expressed per hundred. *A high percentage.*
- Percentage point — the arithmetic difference between two percentages. *Up two percentage points.*
Word forms
| Form | Word | Example |
|---|---|---|
| Noun (US) | percent | Ten percent. |
| Two words (UK) | per cent | Ten per cent. |
| Noun | percentage | A small percentage. |
| Symbol | % | 15% |
| Related | percentile | The 90th percentile. |
How it is used in a sentence
- Unemployment rose by one percentage point.An arithmetic difference.
- Sales rose ten per cent.A proportional change.
- She scored in the top percentile.Percentiles rank, they do not measure amounts.
Percentage traps
- Point versus percent — the classic confusion
- Percentage of what? — the base matters more than the figure
- Up 50% then down 50% — leaves you below where you started
- Averaging percentages — usually wrong without weighting
- Percentile — a rank, not a proportion
From Latin *per centum*, by the hundred. British English usually writes it as two words; American English joins them. The % symbol evolved from an abbreviation of the Italian *per cento*.
Percent or per cent?
Percent is standard in American English, per cent in British. Both are correct in their own varieties.
Why does 50% down not undo 50% up?
Because the second percentage applies to a different base. A hundred rises to 150, and half of 150 is 75.