Percentage Increase Calculator
Enter the original value and the new value to calculate the percentage increase (or decrease).
Quick Answer
To calculate percentage increase, subtract the old number from the new number, divide by the old number, and multiply by 100.
In short: ((New - Old) / Old) × 100
Step-by-Step: How to Calculate Percentage Increase
1) Find the difference
Subtract the original amount from the new amount:
Difference = New Value - Original Value
2) Divide by the original value
This tells you how large the change is compared to where you started:
Relative Change = Difference ÷ Original Value
3) Convert to a percentage
Multiply the relative change by 100:
Percentage Change = Relative Change × 100
Example
Suppose a price goes from $50 to $65.
- Difference = 65 - 50 = 15
- Relative change = 15 / 50 = 0.30
- Percentage increase = 0.30 × 100 = 30%
So the price increased by 30%.
Common Mistakes to Avoid
- Using the new value in the denominator. Use the original value as the base.
- Forgetting to multiply by 100. A decimal like 0.2 means 20%.
- Mixing up increase and decrease. A negative result indicates a decrease.
- Confusing percent change with percentage points. These are not the same thing.
Percentage Increase vs Percentage Points
If interest rates rise from 5% to 7%, that's:
- 2 percentage points (7% - 5%)
- 40% increase because (2 ÷ 5) × 100 = 40%
Use percentage points when comparing two percentages directly. Use percentage increase when describing relative growth.
Real-Life Uses
Salary growth
If your salary rises from $60,000 to $66,000, the increase is 10%.
Rent or grocery prices
Percentage increase helps show inflation impact over time.
Website traffic and business metrics
Marketers track percentage increase in conversions, click-through rate, and customer signups to measure campaign performance.
Investments
When your investment grows from one value to another, percentage increase gives a quick way to compare growth across different assets.
How to Calculate the New Value from a Percentage Increase
If you know the original value and the increase percentage, use:
New Value = Original Value × (1 + Percentage/100)
Example: 120 increased by 15%:
120 × (1 + 15/100) = 120 × 1.15 = 138
How to Find the Original Value
If you know the new value and the percentage increase, rearrange the formula:
Original Value = New Value ÷ (1 + Percentage/100)
Example: A value is now 240 after a 20% increase:
Original = 240 ÷ 1.20 = 200
What if the Result Is Negative?
A negative percent change means the value went down, not up. In that case, report it as a percentage decrease.
Example: From 100 to 80:
- Difference = -20
- -20 / 100 = -0.20
- -0.20 × 100 = -20%
That is a 20% decrease.
FAQ
Can percentage increase be over 100%?
Yes. If a value more than doubles, the increase is greater than 100%.
Why does base value matter?
Because percentages are relative. A $10 change is huge on a $20 base (50%) but small on a $500 base (2%).
Can I calculate percentage increase in Excel or Google Sheets?
Yes. Use: =(New-Old)/Old and format the cell as a percentage.
Final Takeaway
The easiest way to remember percentage increase is:
Change ÷ Original × 100
Use the calculator above for quick results, and use the step-by-step method when you want to show your work clearly.