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Math

Percentage Change Calculator

Compare starting and ending values to find percentage change plus the absolute difference.

percent changeincreasedecrease
Percentage Change

Compare a starting value with an ending value to find the percent move and raw delta.

Percent change (%)
+25
Difference
+20
Ratio (end ÷ start)
1.25
Direction
Increase

Percent change formula

Percent change = ((end − start) / start) × 100

Positive results show gains, negative results show losses. A zero start value produces an undefined percent change.

How to use

  1. Enter the starting value.
  2. Enter the ending value you want to compare against the start.
  3. Review the percent change and the raw difference below the inputs.

Example

Input: Start = 80, End = 100

Output: Percent change = +25%, Difference = +20

Student-friendly breakdown

This walkthrough emphasizes the most searched ideas for Percentage Change Calculator: percentage change calculator, percent increase calculator, percent decrease calculator, percentage difference calculator. Start with the formula above, then follow the guided steps to double-check your work. For quick revision, highlight the givens, plug into the equation, and finish by verifying your units.

Need more support? Use the links below to open the long-form guide, browse additional examples, or hop into adjacent calculators within the same topic — each one is a quick way to double-check your work or handle a related question without starting from scratch.

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Deep dive & study plan

Percentage Change Calculator: Computes percent difference between a starting and ending value. It's built around percent change, increase, decrease, so you can go from a raw question to a checked answer without switching tools.

The math behind it: Positive results show gains, negative results show losses. A zero start value produces an undefined percent change. The core relationship is Percent change = ((end − start) / start) × 100, shown above the calculator so you can see exactly how your inputs turn into the result.

To use it well: (1) Enter the starting value. (2) Enter the ending value you want to compare against the start. (3) Review the percent change and the raw difference below the inputs. Keep your units consistent as you go, and re-run a case you already know the answer to — it's the fastest way to catch a typo before it throws off a result you're relying on.

Worked example: entering Start = 80, End = 100 returns Percent change = +25%, Difference = +20. Try swapping in your own numbers next, especially a case you're unsure about, before you use this for something that matters.

Quick retention checklist

  • Speak the formula aloud (or annotate it) so the relationships stick.
  • Write each step in your own words and compare with the numbered list above.
  • Swap in new numbers for the Example to make sure the calculator (and your logic) handles edge cases.
  • Check at least one related calculator below — it's the fastest way to confirm your numbers still line up from a different angle.

FAQ & notes

What if the starting value is zero?

Percent change cannot be computed when the baseline is zero, so the calculator marks the result as undefined.

How do I interpret a negative result?

A negative percent change means the ending value is smaller than the starting value, indicating a decrease.

What formula does the Percentage Change Calculator use?

Positive results show gains, negative results show losses. A zero start value produces an undefined percent change.

How do I use the Percentage Change Calculator?

Enter the starting value. Enter the ending value you want to compare against the start. Review the percent change and the raw difference below the inputs.