Percentage Change Calculator
Calculate percentage change, percentage of a number, and what percent a number is of another
ℹ️ About Percentage Change Calculator
The Percentage Change Calculator handles three related questions in one place: the percent change from an old value to a new one, what X percent of a number equals, and what percentage one number is of another. Change mode reports the signed percentage alongside the raw difference and labels the move as an increase or decrease, which suits price rises, grade shifts, traffic or revenue comparisons. Every result can be copied as a one-line summary, and the maths runs in your browser.
💡 Use Cases
📋 How to use
Choose what you want to work out: percentage change, percentage of a value, or the value behind a percentage.
Enter the original (old) value in the first field, for example 100.
Enter the new value in the second field, for example 150.
Read the result: the calculator shows the percentage increase or decrease along with the absolute difference.
Use the copy button to grab the result, or adjust either value to recalculate instantly.
💎 Pro Tips
- Enter your values carefully — small differences in inputs can lead to large changes in the Percentage Change result, especially for long time periods.
- Use the Percentage Change to compare multiple scenarios side by side. Open the tool in several tabs to see how different assumptions impact your outcome.
- Bookmark this Percentage Change and return whenever your situation changes — small updates in income, rates, or expenses are easy to recompute.
- Export or copy the result before closing the tab. Since the Percentage Change stores no data server-side, your inputs reset when you navigate away.
- Combine this Percentage Change with our other financial tools (loan, tax, budget calculators) for a more complete financial picture.
❓ Frequently Asked Questions
Yes. The Percentage Change is 100% free, with no signup, no paywall, no limits, and no watermarks on results. You can use it as often as you need.
No. The Percentage Change runs entirely in your browser. Your inputs stay on your device and are never transmitted to our servers, guaranteeing privacy.
The Percentage Change uses industry-standard formulas and returns mathematically precise results based on the inputs you provide. Always verify with a professional advisor for major decisions.
Yes. The Percentage Change is fully responsive and works on iOS, Android, and all modern mobile browsers with no app install required.
After the initial page load, most calculations run offline because the logic runs in JavaScript on your device. If you lose connection mid-session, you can usually keep calculating.
While the Percentage Change provides accurate computations, it does not replace professional advice. For tax, legal, medical, or major investment decisions, consult a certified advisor.