Relative Change Calculator
Calculate the percentage change between two values.
Shows absolute difference, relative percent change, and whether the change is an increase or decrease.
Relative change measures how much a value shifted relative to where it started:
Relative change (%) = (new − old) / |old| × 100
If a stock goes from $80 to $100, the absolute change is $20 but the relative change is +25%. That percentage is more useful when comparing across different scales — a $20 gain on a $100 stock is very different from a $20 gain on a $2,000 stock.
The denominator uses the absolute value of the old value, which handles the case where the starting value is negative. If revenue was −$50 thousand (a loss) and improved to −$10 thousand, the relative change is (−10 − (−50)) / 50 × 100 = 80% improvement.
A few edge cases worth knowing:
If the old value is zero, relative change is undefined (division by zero). Absolute change still works, but percentage change does not.
If the new value is zero, relative change is −100%. That is a complete wipeout.
If both are the same, relative change is 0%.
Relative change vs percentage points: an interest rate rising from 4% to 6% is a 2 percentage point increase but a 50% relative change. Mixing these up is a classic error in news reporting.
This calculator shows the sign — positive for increases, negative for decreases. It always uses the old value as the reference, which is the standard mathematical definition.
How we build and check this calculator
This calculator runs entirely in your browser, so the numbers you enter stay on your device. The math behind it is written by hand and tested against worked examples and standard references before the page goes live.
SuperGlobalCalculator is independently built and maintained. See how we build and verify our calculators.