Percentage Increase Calculator
The percentage increase calculator has two modes. In the first mode, you enter an original value and a percentage, and the calculator returns the new value after a percentage increase is applied. For example, if an item costs 100 dollars and the price increases by 20%, the new price is 120 dollars. In the second mode, you enter the original value and the new value, and the calculator returns the percentage increase between them. For example, if a quantity was 50 and is now 75, the percentage increase is 50%. Percentage increase is useful for understanding growth in prices, salaries, populations, or any other quantity. It provides a relative measure of change that is easier to compare across different scales than absolute change. The calculator uses the formulas: new value = original * (1 + percentage / 100) and percentage increase = ((new - original) / original) * 100.
Percentage increase formula
New value = original value * (1 + percentage / 100)
Absolute increase = new value - original value
Percentage increase = ((new - original) / original) * 100
Examples
| Original | Percentage increase | New value | Absolute increase |
|---|---|---|---|
| 100 | 20% | 120 | 20 |
| 50 | 50% | 75 | 25 |
| 1,000 | 10% | 1,100 | 100 |
| 200 | 25% | 250 | 50 |
| 75 | 100% | 150 | 75 |
Why a 50 percent loss needs a 100 percent gain to recover
Percentage rises and falls are not mirror images, because each is measured against a different base. Lose 50 percent of an amount and you are left with half; to climb back you must now double what remains, a 100 percent gain, just to reach the original figure. The larger the fall, the more lopsided the recovery: a 20 percent drop needs a 25 percent rise, but an 80 percent drop needs a 400 percent rise to break even.
This asymmetry is why sequential percentage changes never simply cancel. A 10 percent increase followed by a 10 percent decrease leaves you slightly below where you started, not exactly back, because the decrease acts on the enlarged number. Over many steps these small gaps compound, which is why investment returns are properly measured by the compounded result, not by adding the yearly percentages.
The practical lesson is to be precise about the base of every percentage change and to distrust intuition that treats increases and decreases as equal and opposite. When a figure has moved twice, calculate the two steps in order rather than netting the percentages, and read a recovery in terms of the gain actually required, not the loss that occurred.
Percentage increase calculator: frequently asked questions
What is a percentage increase?
A percentage increase is a measure of how much a value has grown relative to its original value, expressed as a percentage. For example, if a price increases from 100 to 120, the percentage increase is 20%. The formula is: percentage increase = ((new value - original value) / original value) * 100.
How do I calculate a percentage increase?
There are two common scenarios. First, if you know the original value and the percentage increase, find the new value using: new value = original value * (1 + percentage / 100). For example, a 100 dollar item with a 20% increase costs 100 * 1.20 = 120 dollars. Second, if you know the original and new values, find the percentage increase using: percentage increase = ((new - original) / original) * 100.
Can percentage increase be negative?
No. Percentage increase only describes growth. If a value decreases, that is a percentage decrease, not a negative percentage increase. For example, going from 100 to 80 is a 20% decrease, not a -20% increase.
What is the difference between percentage increase and absolute increase?
Absolute increase is the raw difference: new value - original value. Percentage increase expresses this as a percentage of the original value. For example, if a value goes from 100 to 110 and another from 1,000 to 1,010, both have an absolute increase of 10, but the first has a 10% increase and the second has a 1% increase.
How do I reverse a percentage increase?
If you know the new value and the percentage increase, find the original value by dividing: original value = new value / (1 + percentage / 100). For example, if 120 is after a 20% increase, the original was 120 / 1.20 = 100.
Official sources
- Standard mathematical formula for percentage increase.
- NIST Special Publication 330: The International System of Units.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.