Start with what the numbers represent
Suppose a survey finds that 20% of respondents chose an option in one round and 25% chose it in another. How much did the share rise? The answer depends on the question. The difference between the two shares is five percentage points. Compared with its original level of 20%, the share rose by 25%. Both statements describe the same movement, but they use different reference points.
A percentage is a proportion expressed out of 100. A percentage point is a unit for the difference between two percentages. Percentage change, by contrast, describes a difference relative to a starting value. Before choosing a calculation, ask whether you want to report the distance between two rates or the size of a change compared with where you started.
Calculate percentage-point change by subtraction
To find a percentage-point change, subtract the earlier percentage from the later percentage: later percentage − earlier percentage. If a course completion rate rises from 60% to 72%, the change is 72% − 60% = 12 percentage points. If it falls from 72% to 60%, the change is −12 percentage points, or a decrease of 12 percentage points.
This measure is especially useful when comparing rates, shares, and other figures already stated as percentages. For example, a change in a response rate from 8% to 10% is a two-percentage-point increase. Saying it rose by two percentage points tells readers exactly how far apart the two rates are on the percentage scale. It does not, on its own, say how large the increase is relative to the original rate.
Calculate percentage change using the starting value
For percentage change, subtract the starting value from the ending value, divide by the starting value, and multiply by 100: ((ending value − starting value) ÷ starting value) × 100. If a team processes 80 requests in one period and 100 in the next, the increase is 20 requests. Relative to the starting 80, that is (20 ÷ 80) × 100 = 25%.
The same formula works when the values themselves are percentages. A rate that rises from 20% to 25% increases by five percentage points, but its percentage change is ((25 − 20) ÷ 20) × 100 = 25%. A rate that rises from 2% to 3% increases by just one percentage point, yet its percentage change is 50%. These examples show why a relative increase can sound large even when the change on the percentage scale is small.
The starting value matters. Going from 80 to 100 is a 25% increase, while returning from 100 to 80 is a 20% decrease. The absolute difference is 20 in both directions, but the calculation uses a different starting value each time. If the starting value is zero, the usual percentage-change formula cannot be calculated because it would require division by zero.
Choose the measure that answers your question
Use percentage points when your main question is how far apart two percentages are. Use percentage change when your main question is how large a change is relative to the initial value. You can report both if each adds useful context: “The share increased from 20% to 25%, a rise of five percentage points, or 25% relative to its initial level.” Stating the original and final figures lets readers check either calculation.
Keep the comparison consistent. If two percentages come from groups of different sizes, a percentage-point difference still describes the gap between their rates; it does not tell readers how many people are involved. If you need to describe a change in the number of people, use the counts and calculate from those instead. Also check that the two figures use comparable definitions and time periods. Arithmetic cannot resolve a comparison if what was measured changed.
Make the wording unambiguous
Avoid saying that a rate “rose by 5%” when you mean it moved from 20% to 25%. Many readers will understand “rose by 5%” as a relative increase, which would put the new rate at 21%. Write “rose by five percentage points” for the subtraction, or “rose by 25% relative to its starting rate” for the percentage change.
When presenting findings, include the starting and ending values alongside the change, and name the unit. That small habit makes it easier to spot calculation errors and harder to confuse an absolute difference with a relative one. If either value is rounded, consider whether the reported change should also be rounded: calculating from more precise underlying figures can produce a result that does not exactly match subtraction of the displayed numbers.
