Percentage Change Calculator
Track growth, decline, and delta. Instantly calculate the percentage increase or decrease between two values for finance, health, or statistics.
Did You Grow or Shrink?
Numbers change constantly. Stock prices rise, weight drops, populations shift. But raw numbers rarely tell the whole story. A $10 increase is huge if you started with $5, but meaningless if you started with $1,000,000. Our Percentage Change Calculator contextualizes these shifts, giving you the relative growth or decline rate instantly.
Understanding Percent Change
**Percentage Change** represents the degree of change over time. It is used for many purposes in finance, mathematics, physics, and everyday life.
- Percentage Increase: When the new value is larger than the old value.
- Percentage Decrease: When the new value is smaller than the old value.
The Formula
We use the universal formula for relative change:
Where:
V1 = Initial Value (Start)
V2 = Final Value (End)
Finance
"Last year I made $50k, this year I made $65k." That's a 30% raise! Understanding this percentage helps you compare your growth to inflation.
Weight Loss
"I lost 10 lbs." If you started at 200 lbs, that's a 5% loss. This metric helps set realistic health goals regardless of starting size.
Shopping
"The price dropped from $120 to $90." That is a 25% discount. Using percentages helps you spot the best deals across different items.
Frequently Asked Questions
Can percentage decrease be more than 100%?
Generally, no. If a price drops by 100%, it becomes zero (free). If it drops by more than 100%, the seller would be paying you to take it! However, in debt scenarios or temperature, values can go negative.
Why is it different if I reverse the numbers?
Percentages are relative to the *starting* number. Increasing from 50 to 100 is a 100% gain. Decreasing from 100 to 50 is only a 50% loss. This asymmetry is a key concept in math.
How do I calculate "markups"?
A markup is simply a percentage increase from the Cost Price to the Selling Price. Cost $10 -> Sell $15 is a 50% increase (markup).
Math Accuracy
Calculations are precise to typical floating-point standards. Results with negative starting values rely on the absolute value method for direction.
Data Privacy
We do not store your data. This calculator runs entirely in your browser.