Percentage Change vs. Percentage Points: A Crucial Difference
Confusing percentage change with percentage points is one of the most common errors in everyday math and media reporting. Here's the clear distinction with examples.
The Core Distinction
These two terms measure different things and should never be used interchangeably:
- Percentage change — how much a value changed relative to its starting value, expressed as a percentage. Formula: (new − old) ÷ old × 100.
- Percentage points — the arithmetic difference between two percentage values. No division required. If something goes from 20% to 25%, it increased by 5 percentage points.
The confusion arises when the thing you're measuring is already expressed as a percentage. When a percentage value changes, you can describe that change in two ways — and they give very different numbers.
The Classic Example
A bank raises its savings account interest rate from 2% to 3%.
Percentage change: (3 − 2) ÷ 2 × 100 = +50%
Both statements are mathematically correct. But they tell completely different stories. "The interest rate went up by 1 percentage point" is precise and modest. "The interest rate increased by 50%" sounds dramatic. A bank advertising its rate change would likely use "50% increase." A journalist covering rising interest burdens would also likely say "50% increase." A statistician would use "1 percentage point."
More Examples
| Scenario | Starting value | New value | Percentage points | Percentage change |
|---|---|---|---|---|
| Mortgage rate | 4% | 7% | +3 pp | +75% |
| Unemployment rate | 3.5% | 4.5% | +1 pp | +28.6% |
| Approval rating | 52% | 48% | −4 pp | −7.7% |
| Credit card APR | 20% | 25% | +5 pp | +25% |
Mortgage rates rising from 4% to 7% is described as either "+3 percentage points" or "+75% higher rates." The percentage-point description is precise about magnitude. The percentage change framing feels alarming — which is why it appears in headlines more often.
Where the Confusion Causes Real Problems
Inflation coverage: "Inflation fell by 50%" may mean inflation went from 8% to 4% — still 4% inflation, still rising prices, but the rate of increase slowed. This is meaningfully different from prices actually falling.
Tax policy debates: Raising the top income tax rate from 37% to 40% is a 3-percentage-point increase but an 8.1% increase in the tax rate. Critics will use 8.1%. Supporters of the increase will use 3 percentage points. Neither number is wrong.
Investment returns: A fund underperforming a benchmark by 2% (when the benchmark returned 10% and the fund returned 8%) is a 2-percentage-point gap — but not a "2% worse" fund (which would imply 8% × (1 − 0.02) = 7.84%). The fund returned 2 percentage points less, or 20% less than the benchmark.
The Simple Rule
When both values you're comparing are already percentages:
- To describe the arithmetic difference: use percentage points.
- To describe the proportional change in the rate itself: use percentage change.
When the values you're comparing are counts or measurements (prices, population, revenue):
- Always use percentage change. Percentage points do not apply.
Key points
- Percentage points = arithmetic difference between two percentage values (no division).
- Percentage change = proportional change relative to the starting value (requires division).
- When a rate goes from 2% to 3%, that is 1 percentage point up OR 50% increase — both correct, very different implications.
- Media and marketing often use percentage change (which sounds larger) when percentage points would be more informative.
- Basis points are used in finance: 1 basis point = 0.01 percentage points.
Frequently Asked Questions
How do I know which one to use?
Use "percentage change" when comparing two values on a continuous scale (prices, counts, measurements). Use "percentage points" when the values themselves are percentages or rates (interest rates, approval ratings, tax rates).
Why does this distinction matter?
Because the same underlying change can be described very differently depending on which term you use. A rate going from 2% to 3% is a 1 percentage point increase, but a 50% increase in the rate. These tell different stories. Both are technically true, which is why the choice matters for accurate communication.
What is basis points?
A basis point (bp) is one hundredth of a percentage point — 0.01%. Used mainly in finance and central banking. When the Federal Reserve raises rates by 25 basis points, it means an increase of 0.25 percentage points (e.g., from 5.00% to 5.25%).
Is "percentage increase" the same as "percentage change"?
Percentage increase and percentage change are calculated the same way. "Percentage change" covers both increases (positive) and decreases (negative). "Percentage increase" implies a positive direction.
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