SpecWhale

Percent Change Calculator

Find percentage increase or decrease from an old value to a new value.

Formula and method

This calculator uses the values you enter and applies the calculation immediately in your browser. The main output formulas are:

  • Percent change: (newValue - oldValue) / oldValue * 100

Some formulas are undefined for certain input combinations, such as division by zero, equal x-values in a slope calculation, or logarithms of non-positive numbers. In those cases the live tool reports that the result is undefined instead of displaying Infinity or NaN.

Examples

  • Example: with Old value = 80, New value = 100, this calculator returns Percent change = 25 %.
  • Share this page with a clean URL: https://specwhale.com/tools/percent-change-calculator/
  • Try related business & shopping tools when your next step needs another conversion or calculation.

Embed this tool

Paste this snippet into your own site or blog post to embed a live, working copy of this tool. It links back to the full page on SpecWhale.

Frequently asked questions

Is Percent Change Calculator free to use?

Yes. Percent Change Calculator is completely free, has no usage limit, and does not require an account, email, or API key.

Does Percent Change Calculator store or upload my data?

No. Percent Change Calculator calculates everything locally in your browser. Nothing you type is sent to a server or stored by SpecWhale.

How accurate is Percent Change Calculator?

Percent Change Calculator uses a standard formula (see the Method section above for the exact expression). For high-stakes financial, medical, or legal decisions, confirm the result with a professional or an authoritative source before relying on it.

Can I embed Percent Change Calculator on my own website?

Yes. Use the "Embed this tool" snippet on this page to add a free, working copy of Percent Change Calculator to your own blog post or page.

SEO and sharing notes

This page has a single clean canonical URL, descriptive metadata, breadcrumb structured data, and internal links to related tools. Supported calculators and converters can also copy a prefilled share link without changing the canonical index URL.