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Percent Change Calculator

Enter the original value and the new one. See whether it rose or fell, by how much, and the percent change worked out step by step.

Try:

Answer

Enter your numbers or pick an example — the answer and the steps appear here instantly.

How it works

  1. Enter the starting value

    Type the original value in the first box, such as last month's figure. It can be a decimal, a fraction or a negative number, but not 0.

  2. Enter the new value

    Put the later or changed value in the second box, or start from one of the example chips.

  3. Calculate

    The result shows the difference, the percent change with a + or − sign, and a plain verdict: increase, decrease or no change.

  4. Explore the reasoning

    Copy the answer, or open “Explain step by step” for an AI-written walkthrough. Read it critically, because AI explanations are not error-proof.

What the result includes

  • A signed percent

    A rise from 80 to 92 shows +15%. A fall from 92 to 80 shows ≈ −13.04%, with a Rounded tag because the exact value never terminates.

  • The raw difference

    You also get new minus original, so you can quote both the amount of the change and its rate.

  • Exact under the hood

    The calculator keeps the exact fraction, −300/23 % in that example, and rounds only what is displayed. It runs in your browser, free and without an account.

How to calculate percent change by hand, and why percentage points differ

The formula is percent change = (new − original) ÷ |original| × 100. From 80 to 92 the difference is 12, 12 ÷ 80 = 0.15, and 0.15 × 100 = 15, so the value rose by 15%.

The starting value is the base, so direction matters. Going back from 92 to 80 is a difference of −12 measured against 92, which is about −13.04%, not −15%. A change from 0 has no percent at all, because you cannot divide by zero, which is why an original value of 0 is rejected.

Dividing by the absolute value of the original keeps the sign meaningful for negative numbers. A net loss that shrinks from −50 to −20 has gone up by 30, and 30 ÷ 50 = 60%, so the result is +60%, an increase, as common sense says it should be.

When the values are themselves percentages, watch the wording. An interest rate moving from 4% to 5% went up 1 percentage point, but its percent change is (5 − 4) ÷ 4 × 100 = 25%. Both statements are true; they answer different questions.

Frequently asked questions

A percentage increase is a percent change that happens to be positive. This calculator handles both directions; if you want to raise a value by a given percent instead, the percentage increase calculator has a mode for that.

Percent change divides by the original, and division by zero is undefined. Going from 0 to 5 is a real change of 5, but it has no meaningful percentage.

It means the new value is smaller than the original, so the quantity decreased. A result of −25% says the value lost a quarter of where it started.

Each change is measured from a different base. 100 up 50% is 150, and 50% of 150 is 75, so you end at 75 rather than 100.

Not for the calculator: answers and steps are computed on your device without signing in. The optional AI explanation is part of the Pro plans* (*fair use: up to 300 daily runs across the writing, study and code tools); accounts with no plan spend 2 credits on it, and signed-out visitors get a free preview of the beginning.

Yes, to check your setup and your arithmetic. Make sure your course permits calculator and AI help before relying on it for graded work, and show your own working wherever it is required.

More ways to compare numbers

Compare before and after

Enter both values and get the signed percent change with a full step outline.

Find percent change
  • Increase or decrease labeled
  • Difference shown too
  • Rounded only for display