How to Calculate Percent Increase: Formula & Examples
Learn how to calculate percent increase with the standard formula, step-by-step examples, common mistakes, percentage-point differences, and shortcuts.
Percent increase is used whenever a number grows: prices, salary, sales, rent, population, grades, investment values, and more. Knowing how to calculate percent increase helps you compare growth fairly because it measures the change relative to the starting value. A $10 increase is huge on a $20 item but small on a $1,000 item. Percent increase solves that by showing the change as a percentage of the original amount.
What Is Percent Increase?
Percent increase is the amount a value grew compared with its original value.
The formula is:
Percent Increase = ((New Value - Old Value) รท Old Value) ร 100
The old value is the starting point. The new value is the ending point.
How to Calculate Percent Increase
Follow these steps:
- Subtract the old value from the new value.
- Divide the increase by the old value.
- Multiply by 100.
Use our free Percentage Calculator to calculate percent increase instantly.
Step-by-Step Example
A product price rises from $80 to $100.
Step 1 - Find the increase: $100 - $80 = $20
Step 2 - Divide by the old value: $20 รท $80 = 0.25
Step 3 - Multiply by 100: 0.25 ร 100 = 25%
The price increased by 25%.
Percent Increase Examples
| Old Value | New Value | Increase | Percent Increase |
|---|---|---|---|
| 50 | 60 | 10 | 20% |
| 100 | 125 | 25 | 25% |
| 200 | 260 | 60 | 30% |
| 1,000 | 1,050 | 50 | 5% |
| 75 | 150 | 75 | 100% |
A 100% increase means the value doubled. A 200% increase means the value tripled from the original.
Percent Increase vs. Percentage Points
Do not confuse percent increase with percentage points. If an interest rate rises from 4% to 5%, it increased by 1 percentage point. But the percent increase is:
(1 รท 4) ร 100 = 25%
This distinction matters for rates, survey results, margins, and financial reporting.
Percent Increase from Small Numbers
Percent increase can look dramatic when the starting number is small. If a website grows from 10 visits to 30 visits, the increase is 20 visits:
(20 รท 10) ร 100 = 200%
That is a real 200% increase, but the absolute change is still only 20 visits. For honest reporting, it often helps to show both the percentage increase and the actual number change.
| Old Value | New Value | Absolute Increase | Percent Increase |
|---|---|---|---|
| 10 | 30 | 20 | 200% |
| 100 | 120 | 20 | 20% |
| 1,000 | 1,020 | 20 | 2% |
The same increase of 20 produces very different percentages because the starting value changes.
Common Mistakes
Dividing by the new value gives the wrong result. Percent increase is measured against the old value.
Forgetting to multiply by 100 leaves the answer as a decimal. 0.25 means 25%.
Subtracting in the wrong order can turn an increase into a decrease. Use new minus old.
Adding multiple percent increases directly can be misleading if each increase uses a new base.
Practical Uses
Percent increase is useful for:
- Salary raises
- Rent increases
- Price changes
- Revenue growth
- Website traffic growth
- Investment value changes
- Grade improvement
For broader percent problems, read our full guide on how to calculate percent or use the Discount Calculator for sale-price decreases.
Reverse Percent Increase
Sometimes you know the new value and the percent increase, but you need the original value. Use:
Original Value = New Value รท (1 + Increase Rate)
If a price is $120 after a 20% increase, the original price was:
$120 รท 1.20 = $100
This reverse method is useful for taxes, markups, salary changes, and price history. It also helps you check whether advertised increases are being described from the correct starting value.
Frequently Asked Questions
How to calculate percent increase between two numbers?
Subtract the old number from the new number, divide by the old number, and multiply by 100. For example, from 40 to 50, the increase is 10. Then 10 รท 40 = 0.25, so the percent increase is 25%.
What is the formula for percent increase?
The formula is ((New Value - Old Value) รท Old Value) ร 100. The old value must be the starting number. The new value is the ending number after the increase.
How do I calculate a salary percent increase?
Subtract old salary from new salary, divide by old salary, and multiply by 100. If salary rises from $50,000 to $55,000, the increase is $5,000. Then $5,000 รท $50,000 = 0.10, or a 10% raise.
Can percent increase be more than 100%?
Yes. If a value more than doubles, percent increase is above 100%. For example, if sales rise from 30 units to 90 units, the increase is 60 units. Since 60 is 200% of 30, sales increased by 200%.
What if the old value is zero?
Percent increase from zero is undefined because the formula requires dividing by the old value. You can describe the absolute change instead, such as โincreased from 0 to 25,โ but a standard percent increase cannot be calculated.
The Bottom Line
To calculate percent increase, subtract the old value from the new value, divide by the old value, and multiply by 100. Always use the original value as the base, because percent increase measures growth relative to where you started.
Use our free Percentage Calculator to calculate percent increase quickly and avoid formula mistakes.
How to Calculate: Step-by-Step Guide
Identify Old and New Values
Note the starting value (old) and the final value after the increase (new).
Calculate the Difference
Subtract the old value from the new value to find the absolute amount of the increase.
Divide by the Starting Value
Divide the absolute increase by the original old value to get a decimal.
Convert to Percentage
Multiply the decimal result by 100 to find the percent increase.
Verify the Result
Ensure you used the old value as the divisor, as percent increase is measured relative to the starting point.