Percentage Change Calculator – Find Percent Change Between Two Values
Calculate the percentage change between an original value and a new value. Works for both increases and decreases. Enter both numbers and get the percent change instantly.
Percentage Change Calculator
Calculate the percentage change between two values. Positive = increase, negative = decrease. Formula: ((new − original) ÷ original) × 100.
How the percentage change formula works
% Change = ((New Value − Original Value) / Original Value) × 100
A positive result indicates an increase; a negative result indicates a decrease. The formula is the same for both—the sign of the result tells you the direction.
Understanding percentage change and when to use it
Percentage change is a versatile metric that works for both increases and decreases. It answers the question: "By what percentage did this value change?" Whether the change is positive or negative, the same formula applies. A result of +15% means a 15% increase; -15% means a 15% decrease.
The formula always uses the original value as the base. This ensures consistency: a change from 100 to 120 and a change from 120 back to 100 are not symmetric in percentage terms. Going from 100 to 120 is a 20% increase; going from 120 to 100 is a 16.67% decrease. The base matters.
Common uses include comparing year-over-year performance, tracking stock price changes, measuring inflation, and analyzing any before-and-after metric. The percentage change calculator handles the math for you—just enter the original and new values. For cases where you know the value only increased or only decreased, the percentage increase and percentage decrease calculators offer a more focused experience.