Percentage Calculator
Four calculation modes for the most common percentage problems in investing: finding a percentage of a value, calculating proportions, and measuring gains or losses.
What is X% of Y?
Quick reference
What is 15% of $500?$75.00
$30 is what % of $200?15%
Stock went from $80 → $100+25% gain
Portfolio down from $50K → $43K−14% loss
Percentage in investing
Percentage calculations are the foundation of investment analysis. Whether you're comparing a stock's daily move, calculating portfolio allocation, or measuring how much an ETF has gained since purchase — every answer is a percentage.
The % change formula used here is (new − old) / |old| × 100. Using the absolute value of the original prevents sign confusion when dealing with negative base values.
For educational purposes only. Not financial advice.