Percentage Increase Calculator
Calculate percentage increase from a positive original value to a higher or equal value. See the formula, worked examples, limits and two-decimal result.
Formula: Percentage increase = ((new − original) ÷ original) × 100%
Enter a positive original value and a new value equal to or greater than the original. Select Calculate; the result is rounded to two decimal places.
The Percentage Increase Calculator measures how much a new value has risen relative to a positive original value. Enter the two values, select Calculate, and the widget returns the increase as a percentage. It uses a fixed arithmetic formula, not AI.
The supported domain is deliberate: the original value must be greater than 0, and the new value must be equal to or greater than the original value. An unchanged value is valid and produces a 0% increase. A lower new value is rejected on this page; use the Percentage Change Calculator when you need to compare an increase or decrease.
How to Use the Percentage Increase Calculator
- Enter a positive number in Original Value.
- Enter a number in New Value that is equal to or greater than the original.
- Select Calculate.
- Read the percentage increase, displayed to two decimal places.
The form starts with 100 and 150. Selecting Calculate returns 50.00%. The initial result remains an em dash until you calculate. Changing either input clears the previous result, so select Calculate again after an edit. Invalid values produce a field-specific message linked to the relevant input.
Percentage Increase Formula and Examples
Percentage increase = ((new − original) ÷ original) × 100%First subtract the original value from the new value. Divide that increase by the original value, then multiply by 100. The original, rather than the new value, is the denominator. This is the standard direction-aware method described in the Central Statistics Office percentage-change guidance.
For 100 increasing to 150, the increase is 50 and (50 ÷ 100) × 100 = 50%. For 240 increasing to 300, the result is 25%. For 90 increasing to 100, the exact result repeats and the interface displays 11.11%. For 80 remaining at 80, the numerator is 0 and the result is 0%.
Input Limits, Rounding and Related Calculators
Zero cannot be the original value because the formula divides by the original; division by zero does not define a percentage increase. Negative inputs and a new value below the original are outside this calculator’s supported comparison model. Compare like with like, such as dollars with dollars or metres with metres.
The calculation uses JavaScript number arithmetic, and the displayed result is rounded to two decimal places. A very small nonzero increase can therefore display as 0.00%. Browser numbers also have a finite range: an extremely small positive original paired with an extremely large new value can overflow to a non-finite result instead of a usable percentage. The ECMAScript Number specification documents that limit; use consistently scaled values if you encounter it.
Use the Exponential Growth Calculator to model repeated percentage growth over time. This calculator covers one increase between two values and does not predict future growth or provide financial advice.
Frequently asked questions
What formula does the Percentage Increase Calculator use?
It uses ((new value − original value) ÷ original value) × 100. The original value is the denominator and must be greater than 0.
What values does this calculator accept?
The original value must be greater than 0. The new value must be equal to or greater than the original value.
What happens when both values are equal?
Equal values are valid. Their difference is 0, so the calculator returns a 0% increase.
Why can’t the original value be zero?
The formula divides by the original value. Division by zero is undefined, so the calculator rejects an original value of 0.
Can I enter decimals or a lower new value?
Decimals are supported. A new value below the original is rejected because this page is limited to percentage increases.
How are results rounded?
The calculator uses JavaScript number arithmetic and displays two decimal places. A very small nonzero increase can therefore display as 0.00%.
Can extremely large values overflow?
Yes. Browser numbers have a finite range, so an extreme ratio can become non-finite. Use consistently scaled values if that happens.