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Percentage change calculator

Find the percentage increase or decrease between two numbers.

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Need Change, Difference? The Percentage change calculator derives it from Original value, New value in one step. For instance, with Original value = 100 and New value = 150 it returns Change = 50% and Difference = 50.

How to use it

  1. Enter your values: Original value, New value.
  2. Read the result instantly: Change, Difference.

Frequently asked questions

How does the Percentage change calculator work?

It takes Original value and New value and derives Change and Difference from them. The calculation is live as you type, so the result updates on every change.

Which values does the calculator ask for?

2 values: Original value and New value. Nothing else is required — no account, no file upload.

What does a typical calculation look like?

With Original value = 100 and New value = 150, the calculator returns Change = 50% and Difference = 50. Those figures come from running this exact tool, so you can reproduce them by entering the same values.

How much does the result change with different inputs?

It moves a lot. Using Original value = 200 and New value = 300 instead, Difference goes from 50 to 100 — which is why it is worth testing a few scenarios rather than trusting a single figure.

What does it give for smaller values?

Scaled down to Original value = 50 and New value = 75, Difference comes out at 25. The relationship is worth checking at both ends before you rely on a single result.

When would I actually use this?

The everyday cases: a discount at the till, a rise or fall between two figures, the price before tax, and working backwards from a total.

What is the most common mistake?

Undoing a percentage by applying it again. Take 20% off 100 and you get 80; add 20% to 80 and you get 96, not 100 — the two operations use different bases.

What is the difference between the Percentage change calculator and the Percentage point change calculator?

This one returns Change and Difference; the Percentage point change calculator returns Change (percentage points) and Relative change. That is the whole difference — open the one whose figure you need.

Is there a tool for the next step?

Percentage increase calculator is the closest one after this: By how much a value grew from an old figure to a new one, as a percentage — and the absolute change. A negative result means it actually fell.

What else is worth having open alongside it?

Percentage difference calculator and Percentage decrease calculator — they come up in the same task often enough to be worth a second tab.

Further reading

All guides →
How-toPercentage Change: Increase and DecreaseSubtract old from new, divide by the old value, times 100. Here's the formula, why increases and decreases aren't symmetric, and where it's used.How-toHow to Calculate a Percentage: 4 Methods with ExamplesA clear guide to percentages: find X% of a number, work out what percent one number is of another, and add or subtract a percentage — with worked examples.ExplainerPercentage Difference vs. Percentage Change vs. Percentage ErrorThree percentages that look alike but answer different questions. Learn the formula for each, when to use it, and why they give different numbers.ExplainerPercentage Points Are Not PercentMoving from 4% to 5% is a rise of one percentage point and a rise of twenty-five percent. Both statements are true, which is exactly why the ambiguity is so easy to exploit — and why basis points exist.How-toHow to Calculate Percent Error: The Accuracy Formula for SciencePercent error tells you how close a measurement is to the true value. Learn the formula, work through an example, and see how scientists use it to judge accuracy.ExplainerStacked Discounts Do Not Add UpTwenty percent off and then a further ten percent off is not thirty percent off — it is twenty-eight, because the second discount applies to the already-reduced price. The general rule, the cases where order matters, and how sales tax changes the answer.