Work out the difference in percentage points between two percentages, and see the equivalent percentage change — two figures that are easily confused.
These are two different figures that are often mixed up in news reports and statistics. If an interest rate goes from 25% to 30%, it has increased by 5 percentage points — the plain difference between the two shares. But percentage-wise, it has increased by (30 − 25) ÷ 25 = 20%, i.e. relative to the starting value.
The gap between the two grows largest when the starting percentage is low: an increase from 2% to 4% is only 2 percentage points, but a full 100% percentage increase — a doubling. Be precise about which of the two figures you're stating or reading.
Because the two figures can give a completely different impression of the same change. An interest rate going from 2% to 3% has increased by only 1 percentage point, but by 50% percentage-wise — both are correct, but convey different information.
Percentage points are usually right when comparing two shares directly, such as election results, interest rates, or other percentage rates. Percentage change is more appropriate when you want to describe how large the relative change is.
Yes, if the starting percentage ("from") is exactly 0%, percentage change is mathematically undefined (division by zero) — the calculator then only shows the difference in percentage points.