Percentage Calculator

Three quick percentage tools in one: percent of a number, one number as a percent of another, and percent change. Free, instant, private.

1. What is X% of Y?

What is% of ?
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2. X is what percent of Y?

is what percent of ?
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3. Percent increase or decrease from X to Y

Fromto
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How to use the Percentage Calculator

  1. Use the first calculator to find a percentage of a number, such as a tip, discount or tax amount.
  2. Use the second to express one number as a percentage of another, such as a score out of a total.
  3. Use the third to measure the percent increase or decrease between an old value and a new value.
  4. Every field updates the result live as you type, and a plain-English explanation shows the working.

Why use ZillaKit's Percentage Calculator?

Percentages come up constantly — discounts, tips, tax, interest, grades, statistics, price changes — but the three most common questions each need a slightly different formula, and it is easy to mix them up. This calculator lays all three out side by side so you never have to remember which is which. "What is X% of Y" multiplies Y by X divided by 100. "X is what percent of Y" divides X by Y and multiplies by 100. And percent change divides the difference by the original value, which is the step people most often get wrong by dividing by the new number instead. Each result comes with a short worked explanation so you can see exactly how the answer was reached and learn the method for next time. Everything runs instantly in your browser with plain JavaScript, so there is no upload, no signup and no limit. It works the same on your phone or desktop and is handy for shopping, budgeting, schoolwork, spreadsheets and business reporting alike.

FAQ

How do I calculate a percentage of a number?

Multiply the number by the percentage and divide by 100. For example, 15% of 200 is 200 x 15 / 100 = 30. The first calculator does this automatically.

How do I work out what percent one number is of another?

Divide the first number by the second and multiply by 100. For example, 30 out of 200 is 30 / 200 x 100 = 15%.

How is percent increase or decrease calculated?

Subtract the original value from the new value, divide by the original value, and multiply by 100. A positive result is an increase and a negative result is a decrease. Going from 200 to 250 is a 25% increase.

Is my data uploaded anywhere?

No. All three calculators run entirely in your browser using JavaScript. Nothing you type is sent to a server or stored.