Percentage Change Calculator

Enter an original value and a new value and press Calculate change to get the percentage increase or decrease. You can also apply a percentage change to find the new value, or work back to the original.

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What do you want to find?

About this percentage change calculator

Percentage change describes how much a value grew or shrank compared with where it started: the difference between the new and the original value, divided by the original, times 100. It is how price rises, sales growth, weight loss, and test score improvements are usually reported. This calculator gives the change with its direction, the absolute difference, and the ratio of new to old, draws the two values side by side, and shows the arithmetic. It also works backwards: apply a known percentage to find a new value, or remove one to find out what a price was before a markup or discount.

How to calculate percentage change

  1. Choose what to find. Pick Percentage change for two known values, or one of the other modes to find a missing value.
  2. Enter the values. Fill in the boxes that are shown, or press an example such as 80 to 60.
  3. Press Calculate change. Read the change, the chart, and the steps.

Frequently asked questions

How do I calculate a percentage increase?

Subtract the original value from the new one, divide by the original, and multiply by 100. From 100 to 125 the difference is 25, and 25 ÷ 100 × 100 = 25% increase.

Why is a 50% drop not undone by a 50% rise?

Because each percentage is taken from a different starting value. 100 falls by 50% to 50, but 50 rising by 50% only reaches 75. Getting back to 100 needs a 100% increase.

How do I find the price before a discount or tax?

Choose Original value before a change, enter the final price and the percentage. A price of 115 after a 15% increase was 115 ÷ 1.15 = 100. Use a negative percentage for discounts.

What if the original value is zero?

Percentage change from zero is undefined, because any increase from nothing is infinitely large in relative terms. The calculator shows an error; report the absolute change instead.

What is the difference between percent and percentage points?

A rate rising from 4% to 5% is an increase of 1 percentage point but a 25% percentage change. Use this calculator for the relative change and simple subtraction for points.