Percentage Points vs Percent
If an interest rate moves from 4% to 5%, has it gone up by 1% or by 25%? Both answers are defensible, they mean completely different things, and the ambiguity is exploited often enough that it is worth being able to spot.
In short
- A percentage point is an absolute difference between two percentages.
- A percent change is a relative difference, measured against the starting value.
- 4% to 5% is +1 percentage point, and also +25% — both are correct.
- The smaller the starting figure, the wider the gap between the two readings.
Two different questions
The confusion exists because "percent" is doing two jobs. It describes a quantity — 5% of people — and it describes a change in that quantity. When the thing being measured is itself a percentage, the two collide.
Ask "how much bigger is the new figure than the old one, in the units we are already using?" and you get percentage points: 5% − 4% = 1 percentage point. Ask "how much bigger is the new figure than the old one, relative to where it started?" and you get percent change: (5 − 4) ÷ 4 = 25%.
Neither is wrong. They answer different questions, and a number quoted without saying which one is being used cannot be checked.
Why the gap can be enormous
The relative reading depends entirely on the starting point, so the same one-point move looks very different depending on where it starts:
| Change | In percentage points | As a percent change |
|---|---|---|
| 0.5% → 1.5% | +1 point | +200% |
| 2% → 3% | +1 point | +50% |
| 4% → 5% | +1 point | +25% |
| 20% → 21% | +1 point | +5% |
| 50% → 51% | +1 point | +2% |
| 80% → 81% | +1 point | +1.25% |
Every row is the same absolute move of one percentage point. The relative figure ranges from +1.25% to +200%. That is why someone with a case to make will always quote whichever of the two is more dramatic.
How this gets used to mislead
Neither framing is a lie, which is what makes the technique effective. A drug that reduces the chance of an event from 2% to 1% can be described as halving the risk — a 50% reduction — or as reducing it by one percentage point. The first sounds transformative; the second sounds marginal. Both describe exactly the same result.
The honest presentation gives both, or at least gives the underlying numbers so the reader can work out the other. The distinction has a name in medical statistics: the relative risk reduction is the 50% figure, the absolute risk reduction is the one point, and reporting the first without the second is a well-documented way of overstating a benefit.
The same trick appears in unemployment figures, market share, interest rates and election polling. Whenever a percentage changes and the change is itself reported as a percentage, ask which of the two you are being given.
Reading a poll correctly
Polling is where the distinction matters most and is respected most consistently. If a party moves from 30% to 33%, that is a three point move, and reputable coverage will say "three points" rather than "10%".
There is a good reason for the convention. A poll has a margin of error expressed in points — typically around three points for a national sample — so a change measured in points can be compared directly against it. A three point move with a three point margin of error may be nothing at all. Converting that to "up 10%" hides the comparison that tells you whether the change is real.
A note on basis points
Finance uses a third unit to remove the ambiguity entirely. A basis point is one hundredth of a percentage point, so 100 basis points is one percentage point.
It exists precisely because rate movements are small and the percent-versus-points confusion is expensive. Saying a central bank raised rates "by 25 basis points" is unambiguous in a way that "by 0.25%" is not — the latter could be read as a relative change of a quarter of one percent, which would be a very different decision.
How to write it so nobody is confused
Use "percentage points" — or "points" after the first mention — for the absolute difference between two percentages. Reserve "percent" for a relative change, and where a relative change might be mistaken for an absolute one, give the two underlying figures.
"Approval rose from 41% to 45%, up four points" is unambiguous. "Approval rose 4%" is not: the reader cannot tell whether the new figure is 45% or 42.6%. If you have room for only one number, the points figure is usually the more informative, because the reader can reconstruct the relative change from it but not the other way round.
Frequently Asked Questions
What is the difference between a percentage point and a percent?
A percentage point is the plain arithmetic difference between two percentages: 5% minus 4% is one percentage point. A percent change measures that difference relative to the starting value: going from 4% to 5% is a 25% increase. Both describe the same move.
Is a rise from 4% to 5% a 1% rise or a 25% rise?
Both, depending on the question. It is a rise of one percentage point in absolute terms, and a rise of 25% relative to the starting figure of 4%. Saying simply "a 1% rise" is the ambiguous form, because a reader may take it as a relative change and calculate 4.04%.
What is a basis point?
One hundredth of a percentage point, so 100 basis points equals one percentage point. Finance uses the unit because interest rate moves are small and the percent-versus-points ambiguity would otherwise be costly. A 25 basis point rise moves a rate from 4.00% to 4.25%.
Why do news reports about polls use points?
Because a poll carries a margin of error quoted in percentage points, so a change expressed in points can be compared directly against it. A three point move inside a three point margin of error may not be a real change at all, and converting the move to a relative percentage hides that comparison.
How do I calculate the percent change between two percentages?
Subtract the old figure from the new one, divide by the old figure and multiply by 100. From 4% to 5%: (5 − 4) ÷ 4 × 100 = 25%. Note that you divide by the starting value, not by 100 and not by the new value.