Percentage Calculator · Practical guide
How to Calculate Percentage Increase Between Two Numbers
One formula turns any two numbers into a percentage increase or decrease — here is how it works, with examples.
At a glance
The Percentage Increase Formula
To calculate the percentage increase between two numbers, subtract the original value from the new value, divide by the original value, and multiply by 100:
Percentage Change = ((New − Original) ÷ Original) × 100
A positive result is an increase; a negative result is a decrease. If a price rises from $80 to $92, the increase is ((92 − 80) ÷ 80) × 100 = (12 ÷ 80) × 100 = 15%.
Interactive tool
Percentage Calculator
Enter your own values, then compare the result with the examples below.
More Worked Examples
- A monthly bill drops from $250 to $200: ((200 − 250) ÷ 250) × 100 = −20%, a 20% decrease.
- Rent rises from $1,200 to $1,260: (60 ÷ 1,200) × 100 = +5%.
- A stock goes from $45 to $54: (9 ÷ 45) × 100 = +20%.
Quick Reference: Increases From 100
| Original | New Value | Percentage Change |
|---|---|---|
| 100 | 110 | +10% |
| 100 | 125 | +25% |
| 100 | 150 | +50% |
| 100 | 200 | +100% |
| 100 | 75 | −25% |
The Mistake Everyone Makes
Always divide by the original value, not the new one. Going from 80 to 100 is a 25% increase (20 ÷ 80), but going from 100 back to 80 is only a 20% decrease (20 ÷ 100). The same $20 gap produces different percentages because the starting point changed. This is also why a 10% raise followed by a 10% pay cut does not cancel out: $100 becomes $110, then $99.
Frequently Asked Questions
What is the formula for percentage increase?
((New Value − Original Value) ÷ Original Value) × 100. Divide by the original value, and a positive result means an increase.
Can a percentage increase be more than 100%?
Yes. Going from 50 to 200 is a 300% increase, because the gain of 150 is three times the original 50.
Why doesn't a 10% increase followed by a 10% decrease cancel out?
The decrease applies to the larger new value. $100 plus 10% is $110; $110 minus 10% is $99, so you end up 1% behind.
How do I reverse a percentage increase?
Divide the new value by 1 plus the increase as a decimal. If a price rose 25% to $60, the original was $60 ÷ 1.25 = $48.