Overview
Introduction
Whether it's a salary raise, a price hike, or a growing follower count, expressing a change as a percentage makes it much easier to compare than raw numbers alone.
This calculator takes an original value and a new value and instantly returns the percent increase between them.
What Is Percentage Increase Calculator?
A calculator that finds the percentage increase from an original value to a new value, by dividing the difference by the original value and converting it to a percentage.
It runs entirely client-side as part of this site's Math Tools collection, so nothing you enter is ever uploaded to a server.
How Percentage Increase Calculator Works
The original value is subtracted from the new value to get the raw difference, which is then divided by the original value and multiplied by 100.
The calculation happens synchronously in JavaScript the moment you change either input, with no network round trip involved.
When To Use Percentage Increase Calculator
Use it whenever you want to express how much a value grew, a salary, a price, a population, or a metric over time, as a percentage of its starting point.
If the new value could plausibly be smaller than the original, this tool still works correctly, the result will simply come back negative.
Often used alongside Percentage Decrease Calculator, Percentage Change Calculator and Percentage Difference Calculator.
Features
Advantages
- Instant results as you type, with no submit button or network delay.
- Reports the true signed change rather than hiding a decrease behind a forced positive number.
- Simple, single-purpose interface: enter an original value and a new value, get the percent increase.
Limitations
- Cannot compute a result when the original value is zero, since that requires dividing by zero.
- Relies on standard JavaScript floating-point arithmetic, which is precise enough for everyday use but not intended for high-precision financial or scientific computation.
Examples
Best Practices & Notes
Best Practices
- Put the earlier, starting value in 'Original value' and the later value in 'New value', reversing them inverts the meaning of the percentage.
- Treat a negative result as a real decrease rather than an error, the formula intentionally reports the signed change.
Developer Notes
Implemented as `((newValue - originalValue) / originalValue) * 100` on plain JavaScript numbers, returning a discriminated union so a zero original value surfaces as `{ success: false, error }` instead of `Infinity` or `NaN`; the display value is rounded with `trimmedRound` from the Percentage Calculator's lib.
Percentage Increase Calculator Use Cases
- Calculating a salary or price increase from one year to the next
- Measuring the growth of a metric like website traffic or follower count
- Comparing a before-and-after quantity in a report or spreadsheet
Common Mistakes
- Swapping the original and new values, which flips the sign and magnitude of the result.
- Assuming a negative result is a bug rather than a genuine decrease, this tool reports the signed change on purpose.
Tips
- If you specifically want the decrease framed as a positive shrinkage percentage, use the Percentage Decrease Calculator instead.
- If you want the result explicitly labeled as increase, decrease, or no change, use the Percentage Change Calculator.