Instantly calculate percentage increase or decrease between two values — including absolute change and automatic detection of growth or decline.
The Percentage Change Calculator measures how much a value has grown or declined relative to its original amount. Enter an old value and a new value to instantly get the percentage change, absolute change, and whether it's an increase or decrease.
Change Amount = New Value − Old Value Percentage Change = ((New − Old) ÷ Old) × 100
A positive result means an increase; a negative result means a decrease.
These two measures are related but answer different questions:
Example: comparing 100 and 120 gives a percentage change of 20% but a percentage difference of 18.18%.
If the old value is 0, percentage change cannot be computed — dividing by zero is undefined. In practice this situation is typically reported as "not applicable" or ∞.
For calculating a specific percent of a value or finding what percent one number is of another, see the Percentage Calculator.
Subtract the old value from the new value, divide by the old value, then multiply by 100. Formula: ((New − Old) ÷ Old) × 100. Example: from 80 to 100 → ((100 − 80) ÷ 80) × 100 = 25%.
Percentage change divides by the original (old) value — it's directional and shows how much something grew or shrank from a specific starting point. Percentage difference divides by the average of both values — it's symmetric and doesn't treat either value as the 'original.' Going from 100 to 120: percentage change = 20%, percentage difference = 18.18%.
A negative result means the value decreased. For example, a stock price dropping from $100 to $75 gives a percentage change of −25%, which means it lost 25% of its value.
Yes. If the new value more than doubles the old value, the change exceeds 100%. Going from 50 to 150 is +200%; from 50 to 200 is +300%.
Percentage change is mathematically undefined when the old value is 0, because you cannot divide by zero. In practice, this is typically reported as 'not applicable' or 'infinite.'
Enter last year's figure as the old value and this year's figure as the new value. For example, revenue of $120K this year vs $100K last year: ((120 − 100) ÷ 100) × 100 = 20% YoY growth.
Yes. It supports both decimal and negative inputs, making it useful for tracking temperature changes, financial losses, or any metric that fluctuates below zero.