Practical guide
Percent vs percentage points
When a number that is already a percentage goes up or down, there are two honest ways to describe the change, and they can sound wildly different. Knowing which one you are reading helps you see through confusing headlines and compare offers fairly.
The core idea
A percentage point is the simple difference between two percentages. A percent change measures that difference relative to where you started.
An interest rate rises from 4% to 5%.
Percentage points: 5 − 4 = 1 percentage point
Percent change: (5 − 4) ÷ 4 × 100 = 25% increase
Both statements are true. "Rates rose by 1 point" and "rates rose by 25%" describe the exact same event. The danger is writing "rates rose by 1%" when you mean one point, because a 1% rise from 4% would only take the rate to 4.04%.
Interest rates and loans
Interest rate changes are where this distinction matters most to everyday budgets. Here is a simple illustration using interest on a $300,000 balance for one year, ignoring repayments and compounding to keep the arithmetic clear:
At 6%: $300,000 × 0.06 = $18,000 interest
At 7%: $300,000 × 0.07 = $21,000 interest
The rate rose 1 percentage point, but the interest cost rose $3,000, which is 16.7% more.
A one-point move sounds small, yet it changes the cost of borrowing by a sixth in this example. Real loan payments depend on the term and repayment schedule, so use your lender's figures for actual decisions.
Polls, surveys, and statistics
News reports often compare survey results. If support for a proposal moves from 40% to 46%, it has gained 6 percentage points. Relative to its starting level, support grew by 6 ÷ 40 = 15%.
Watch for headlines that pick whichever number sounds more dramatic. A rare event whose likelihood rises from 1% to 2% has "doubled" (a 100% increase), but the change is only one percentage point. Both facts are useful; a fair description usually gives both.
Test scores and grades
A score improves from 80% to 88%.
Points: 88 − 80 = 8 percentage points
Percent change: 8 ÷ 80 × 100 = 10% improvement
Teachers and report cards normally talk in points. If you want the relative improvement, use the percentage increase/decrease calculator with 80 as the original value and 88 as the new value.
Decreases work the same way
If an unemployment rate falls from 10% to 8%, it dropped 2 percentage points. Relative to the starting level, that is a 2 ÷ 10 = 20% decline. The smaller the starting percentage, the bigger the relative change from a one-point move.
Basis points
In finance, rate changes are often quoted in basis points to avoid this confusion entirely. One basis point is one hundredth of a percentage point.
1 basis point = 0.01 percentage points
25 basis points = 0.25 percentage points
100 basis points = 1 percentage point
So when a central bank "raises rates by 50 basis points", a 5.00% rate becomes 5.50%.
How to describe changes clearly
- Use "percentage points" (or "points") for the plain difference between two rates.
- Use "percent" for a change measured relative to the starting value.
- When it matters, give both: "up 2 points, from 10% to 12%, a 20% relative rise".
- Always state the starting and ending values so readers can check the math.
For more traps like this one, see the common percentage mistakes guide.