When a rate moves from 10% to 12%, writers sometimes say “up 2%” when they mean 2 percentage points. The relative increase is 20%. Both numbers can be true; only one matches each phrase.

Percentage points = new percent − old percent. No division by the old rate. Polls, unemployment, and tax rates usually need this absolute gap.

Relative change = (new − old) ÷ |old| × 100. That is what the Percentage Increase Calculator reports when both values are known. Applying a stated percent to a base is a different job—use Percentage Change.

A score rising from 70 to 84 is a 20% relative increase of the points earned, not “14%” unless you meant percentage points on a 0–100 scale and said so. Discounts apply a percent to a price—Percentage Change or the Discount Calculator.