Omnibus

Percentage Calculator

Result

30

15% of 200

  • 100% Free
  • No Sign-Up
  • No Credit Card
  • No Free Trial
  • No Pro Tier
  • No Watermarks

Nothing is uploaded. Just open it and start.

A percentage calculator that runs entirely in your browser

Find a percentage of a number, work out what percent one value is of another, or measure the increase or decrease between two numbers — instantly, with no sign-up and nothing uploaded to a server.

Three modes in one

Percent of a number, what-percent-of, and percentage change — switch with one tap.

Instant results

The answer updates live as you type any value; no calculate button.

Clear working shown

Each result shows the exact expression it came from, so you can double-check it.

100% private

Every calculation happens in your browser. Nothing is uploaded.

Related tools

Discount Calculator

Work out the sale price and how much you save from a percentage discount — or find the percent off from the original and sale price.

CGPA to Percentage Calculator

Convert CGPA to percentage and back using the standard 9.5 multiplier (or your own), plus a 4.0-scale GPA estimate.

EMI Calculator

Calculate your loan EMI, total interest, and total repayment, with a full amortization schedule.

BMI Calculator

Calculate your Body Mass Index from height and weight in metric or imperial, see your BMI category, and your healthy-weight range.

Frequently asked questions

How do I calculate what X% of a number is?
Multiply the number by the percent divided by 100. For example, 15% of 200 is 200 × 0.15 = 30. Choose the "% of" mode and enter 15 and 200.
How do I work out what percentage one number is of another?
Divide the first number by the second and multiply by 100. 30 out of 200 is (30 ÷ 200) × 100 = 15%. Use the "is what %" mode.
How is percentage increase or decrease calculated?
Subtract the old value from the new value, divide by the old value, and multiply by 100. Going from 100 to 150 is a +50% change; 200 to 100 is −50%. Use the "% change" mode.
What happens if I divide by zero?
When the base value is zero the percentage is undefined, so the calculator shows 0 rather than an error.
Is my data stored or uploaded anywhere?
No. Every calculation runs locally in your browser and your last inputs are saved only to this browser's local storage for convenience — nothing is ever sent to a server.
Is the percentage calculator really free?
Yes — nothing to pay, nothing to register for, no watermark. The only revenue here is one modest ad slot on the page.
Do I need to create an account?
No. There's no account system at all. Open the page and start typing.