Free Online Percentage Change Calculator

1. Enter the original (old) value in the first field.
2. Enter the new value in the second field.
3. Read the percent change, the up/down direction, and the absolute difference.
4. Swap the inputs to see how the reverse change is not just the negative of the first.

Percentage change = (new − old) ÷ old × 100. A positive result is a gain, a negative result is a loss. It's the workhorse metric of stock prices, revenue updates, web-traffic reports, and weight tracking.

The key gotcha is that the baseline matters. Going from 100 to 150 is +50%, but going back from 150 to 100 is only −33%. That asymmetry trips up readers and analysts alike — a 50% loss requires a 100% gain to break even. Always re-state which number is the baseline when sharing the figure.

This tool reports the percent change, the direction (↑ increase, ↓ decrease, or no change), and the raw absolute difference so the result is easy to sanity-check. Division by zero is rejected — you can't compute a change from a starting value of zero.