Everyday maths
Percentage points or percent change? Read the difference
A move from 20% to 25% is five percentage points, but a 25% relative increase. Work through both measures without mixing them up.
Imagine a club’s survey response rate rises from 20% to 25%. Saying it “rose by 5%” is ambiguous—and usually not the comparison you mean. There are two useful answers, depending on the question.
Percentage points measure the gap
Subtract the old percentage from the new one: 25 − 20 = 5 percentage points. This directly describes how far apart the two rates are. The Office for National Statistics style guidance distinguishes this subtraction from percentage change.
In the ToolKoru Percentage Calculator (opens in a new tab), choose Percentage-point change. Enter 20 as the original percentage and 25 as the new percentage—not 0.20 and 0.25. The answer is 5 pp, where “pp” means percentage points.
Percent change measures the gap relative to the starting value
Divide the gap by the original value, then multiply by 100: (25 − 20) ÷ 20 × 100 = 25%. The rate is one-quarter higher than it was. This is the same general percentage-change formula explained by the U.S. Bureau of Labor Statistics.
The calculator shows this relative comparison beside the percentage-point result when the original percentage is positive. A clear sentence is: “The response rate rose from 20% to 25%, an increase of 5 percentage points, or 25% relative to the original rate.”
Reversing the change does not reverse the percentage
Now start at 25% and fall to 20%. The gap is −5 percentage points, but the relative change is (20 − 25) ÷ 25 × 100 = −20%. The starting value changed, so the denominator changed. A 25% rise and a 20% fall can take you back to the same rate.
What if the starting rate is zero?
Moving from 0% to 5% is a 5-percentage-point increase. The usual relative-change formula would divide by zero, so no finite relative percentage change can be reported. The tool explains this rather than displaying an invented percentage. For a negative starting percentage it shows the point difference but omits the relative comparison, which can be misleading.
Choose wording that matches the numbers
Use percentage points when comparing two percentage rates directly. Use percent change when asking how large a change is relative to its starting value. Always include the original and new rates when they help the reader. The examples above are arithmetic illustrations, not measured survey results; if the underlying sample changes, check that the rates are genuinely comparable before drawing conclusions.