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Randozi

Percentage Calculator

Three everyday percentage questions in one place — pick the one you need and the answer updates as you type.

X% of Y

12

15% × 80 ÷ 100 = 12

How it works

  1. Choose a mode: “X% of Y”, “X is what % of Y”, or “% change from X to Y”.
  2. Type your two numbers. Decimals work with a dot or a comma.
  3. Read the answer instantly; the line below shows the calculation so you can check it.

What people use it for

  • Shopping and budgets

    Work out 30% of a price, or what share of your budget a single bill takes.

  • Grades and scores

    Turn 42 correct answers out of 50 into a percentage in one step.

  • Prices, sales and stats

    See by how much a price, a salary or a follower count went up or down, in percent.

Questions

What formulas does the calculator use?
X% of Y = X × Y ÷ 100. X as a percent of Y = X ÷ Y × 100. Percent change from X to Y = (Y − X) ÷ |X| × 100, positive for an increase and negative for a decrease.
Why is a 50% increase followed by a 50% decrease not back to the start?
Each percentage applies to a different base. 100 + 50% = 150, but 50% of 150 is 75, so you end at 75, not 100.
Why can't I compute a percent change from 0?
Going from 0 to any other number is an infinite relative change, so there is no meaningful percentage. The calculator says so instead of showing a wrong number.