Percent Change Calculator

About this calculator

This calculator finds the percentage change between an old value and a new value using the formula ((new − old) / old) × 100. A positive result means an increase, a negative result means a decrease — the sign is preserved so you can tell growth from decline at a glance.

It's the standard way to compare prices, stock quotes, populations, salaries, or any two numbers that change over time, and it's used constantly by analysts tracking revenue growth, shoppers comparing sale prices, and students checking homework on percentages. Because it divides by the old value, the tool also handles the common pitfall of confusing percent change with percentage-point change, which trips people up when comparing rates like interest or tax percentages.