Numbrixiya

Percentage calculator

Solve everyday percentage problems in one place: X% of Y, X as a percent of Y, percent change, and add or subtract a percent — each with a clear formula.

Percentage calculator

How to use the percentage calculator

  1. Pick a tab for the problem type you need.
  2. Enter the two values shown for that mode.
  3. Read the result and the substituted formula explanation.
  4. Switch tabs anytime. Sensible sample numbers load for each mode.
  5. Use Reset or Copy result when you want to start over or paste the answer.

Formula & method

X% of Y = (X ÷ 100) × Y.

X is what % of Y = (X ÷ Y) × 100 (Y cannot be zero).

Percent change from X to Y = ((Y − X) ÷ X) × 100 (X cannot be zero).

Add/subtract percent: Y × (1 ± X/100).

%of=(X/100)·Y; is%=(X/Y)·100; Δ%=((Y−X)/X)·100; ±%=Y·(1±X/100)

Worked example

15% of 200 = 30.

25 is what % of 200? 12.5%.

Change from 80 to 100 is +25%. Adding 10% to 200 yields 220.

Frequently asked questions

Why can’t percent change start from zero?

Dividing by zero is undefined. Choose a non-zero starting value or a different mode.

Is percent change the same as percentage points?

No. Going from 10% to 12% is a 2 percentage-point rise, but a 20% relative change.

Does subtract percent allow negative results?

Yes, if you subtract more than 100% of the starting number.

Are calculations private?

Yes. Everything runs in your browser.

Disclaimer

This tool provides estimates only and is not financial, medical, or legal advice.