Percentages are not percentage points
A difference between percentages and a percentage change use different denominators.
The short answer
Percentage points describe subtraction between percentage levels. Relative percentage change divides that difference by the starting percentage. Write out both the operation and the unit when a reader could confuse them.
A worked example
A proportion rises from 20% to 25%. The difference is 5 percentage points. Relative to the original proportion, the increase is (25 − 20) ÷ 20 × 100 = 25%. Saying it rose by “5%” leaves the meaning unclear.
Your turn
A rate falls from 10% to 8%. The decline is 2 percentage points, or 20% of the starting rate. Check which statement your question asks for.
What this does not tell you
An illustrative calculation does not explain causes or predict future results. Check the dates, units and missing observations before using the method elsewhere.
Related term
Percentage pointSources & review
Original Charts Haven example. All stated numbers are illustrative and allow you to repeat the calculation.
Next lesson: Put change in percentages