Toolkit Shelf

Everyday Calculators

Percent Change Calculator

Use this percent change calculator to compare an old value with a new value and see the percentage increase or decrease.

Reviewed May 25, 2026EstimateFormula shown

Live calculator

Percent change

Percent change25.00% increase

Compares the new value with the original value.

Difference20

New value minus original value.

Multiplier1.25x

New value divided by original value.

Formula

Percent change formula

Percent change = ((new value - original value) / original value) x 100

A positive result is an increase. A negative result is a decrease.

How to use

Steps

  1. Enter the original value.
  2. Enter the new value.
  3. Read the percentage increase or decrease.
  4. Use the difference and multiplier to double-check the size of the change.

Example

Sample calculation

Original value80
New value100
Percent change25% increase

Calculator use

Best for

  • Quick percent change from original value and new value.
  • Quick everyday math with the result and formula in one place.
  • Shopping, date, time, unit, school, or household comparisons.
  • A fast check before moving the numbers into a spreadsheet.

Before relying on it

Check first

  • Entering original value and new value from different time periods or scenarios.
  • Mixing units, dates, or original values across the same calculation.
  • Rounding early and then using the rounded number in another step.
  • Copying a result without checking whether the inputs match the real-world question.

Benchmarks

How to read the result

The calculator is a decision aid, not a fixed rule. Use the output to compare scenarios and document your assumptions.

Under 5%Small move

Often normal variation for prices, metrics, and budgets.

5% - 20%Noticeable

Large enough to matter for most everyday comparisons.

20%+Large move

Usually worth checking the inputs and the reason for the change.

Calculator accuracy

Methodology and assumptions

The formula, inputs, example, and limitations are shown so the result is checkable, not just a number in a box.

Formula

Percent change = ((new value - original value) / original value) x 100

Inputs used

Original value, New value

Limitations

Results are estimates for quick planning and should be checked before important financial, legal, tax, health, or business decisions.

Last reviewed

May 25, 2026

Cite this page

Toolkit Shelf. Percent Change Calculator. Retrieved May 25, 2026, from https://toolkitshelf.com/tools/percent-change-calculator

FAQ

Common questions

How do I calculate percent change?

Subtract the original value from the new value, divide by the original value, then multiply by 100.

Is percent change the same as percent difference?

No. Percent change compares a new value against an original value. Percent difference compares two values against their average.

What does a negative percent change mean?

A negative percent change means the new value is lower than the original value.