Percentage Increase Calculator Formula
Understand the math behind the percentage increase calculator. Each variable explained with a worked example.
Formulas Used
Percent Increase
percent_increase = ((new_value - old_value) / old_value) * 100Difference
difference = new_value - old_valueVariables
| Variable | Description | Default |
|---|---|---|
old_value | Original Value | 50 |
new_value | New Value | 75 |
How It Works
How to Calculate Percentage Increase
Formula
Percentage Increase = ((New Value - Old Value) / Old Value) × 100
This formula tells you how much a value has grown relative to the original amount.
Worked Example
A product price increased from $50 to $75. What is the percentage increase?
- 01Difference = 75 - 50 = 25
- 02Percentage Increase = (25 / 50) × 100
- 03= 0.5 × 100
- 04= 50%
When to Use This Formula
- Calculating the year-over-year growth rate of revenue, profit, or user signups to report in business reviews or investor updates.
- Determining how much your rent, insurance premium, or subscription price went up compared to last year, so you can decide whether to negotiate or switch.
- Measuring the percentage change in stock price, portfolio value, or cryptocurrency holdings over a specific time period.
- Comparing price inflation on specific goods — for example, how much grocery costs or gas prices have increased from one year to the next.
- Tracking personal fitness progress by calculating the percentage improvement in weight lifted, distance run, or time achieved.
- Evaluating whether a salary raise keeps pace with inflation by comparing the percentage increase in pay to the CPI increase over the same period.
Common Mistakes to Avoid
- Dividing by the new value instead of the old value — percentage increase is (new - old) / old, not (new - old) / new; using the wrong denominator gives a different and incorrect result.
- Confusing percentage increase with percentage point increase — going from 10% to 15% is a 5 percentage point increase but a 50% relative increase, and mixing these up misrepresents the change.
- Assuming percentage changes are reversible at the same rate — a 50% increase followed by a 50% decrease does not return to the original value; $100 goes to $150 then back to $75.
- Applying the formula when the original value is zero — you cannot calculate a percentage change from zero because division by zero is undefined; use absolute change instead.
- Computing the percentage change between two negative numbers without careful attention to signs — a move from -$500 to -$200 is an improvement but requires care to express it correctly as a 60% improvement, not a negative change.
Frequently Asked Questions
What is percentage increase?
Percentage increase measures how much a value has grown relative to its original amount, expressed as a percentage. Formula: ((New - Old) / Old) × 100.
Can percentage increase be more than 100%?
Yes. If a value more than doubles, the percentage increase exceeds 100%. For example, going from 10 to 30 is a 200% increase because the value grew by 20, which is 200% of the original 10.
What is the difference between percentage increase and the actual increase?
The actual increase is the raw number difference (New - Old). The percentage increase puts that difference in context relative to the starting value. A $100 increase on a $200 item (50% increase) is very different from a $100 increase on a $10,000 item (1% increase).
How do I reverse a percentage increase?
To find the original value before a percentage increase, divide the new value by (1 + percentage/100). For example, if a price increased by 25% to reach $125, the original price was $125 / 1.25 = $100.
Learn More
Guide
How to Calculate Percentages - Complete Guide
Learn how to calculate percentages step by step. Covers finding a percentage of a number, percentage change, reverse percentages, and real-world applications.
Ready to run the numbers?
Open Percentage Increase Calculator