Percentage change measures how much a value rose or fell relative to where it started: from 240 to 276 is a 36-point increase and a 15% change. Choose the "percentage change from X to Y" mode, enter the two values, and the calculator gives the change and the direction. Switch modes to apply a percentage increase or decrease to a number, or to find what percent one number is of another.
The base always matters: a fall from 276 to 240 is a 13% decrease, not 15%, because it is measured against 276. Revenue growth, price changes and inflation all use this same calculation.
Percentage Calculator
The percentage calculator answers the four questions that come up most often in business arithmetic. What is X% of Y is the discount and commission case: 15% of 240 is 36. X is what percent of Y is the share case: 36 is 15% of 240. Percentage change compares two figures over time: from 200 to 250 is a 25% increase, from 250 to 200 is a 20% decrease, and the asymmetry is exactly why growth and decline rates should never be added together. Increase or decrease by X% applies a rate to a base: 240 increased by 15% is 276.
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Frequently Asked Questions
What is the percentage change formula?
(new value − old value) ÷ old value × 100. A negative result is a decrease.
Why is the increase percentage different from the decrease percentage for the same two numbers?
Because each is measured against its own starting value. Going up from 240 to 276 divides 36 by 240 (15%); coming down divides 36 by 276 (13%).
What are percentage points?
The plain difference between two percentages. Moving from 10% to 12% is 2 percentage points but a 20% relative increase.
