percentofthis.com

Type two numbers. The page answers one percentage question, including a tip on a bill, and shows the arithmetic under the result. The math runs in this browser. The numbers are not uploaded.

How a percentage works

Percent means “out of 100.” 18% is 18 out of 100, which is the same as 0.18. To find 18% of 60, divide 18 by 100 and multiply by 60. The result is 10.8.

The other way around asks what share one number is of another. 40 out of 200 is 40 ÷ 200, then times 100, which is 20%. The second number is the whole. It cannot be 0, because there is no share of nothing.

Percent change compares a new number with a starting number. From 80 to 100, the difference is 20. 20 ÷ 80 × 100 is a 25% increase. From 100 to 80, the same steps give a 20% decrease. The starting number cannot be 0.

Percent off removes that share from the original number. 20% off 50 removes 10, so 40 is left. The line under the answer shows the exact steps for the numbers you typed.

A tip is a percent added to a bill. 20% of 84 is 16.80, so the total is 100.80. The tip buttons fill in 15%, 18%, 20%, or 25%. You can type another percent. If more than one person shares the bill, the page divides the total by that number and rounds each share to the cent.

Five questions, worked

• 18% of 60 is 10.8.
• 40 is what percent of 200 is 20%.
• From 80 to 100 is a 25% increase.
• 20% off 50 is 40. The reduction is 10.
• A 20% tip on 84 is 16.80. The total is 100.80.

What this will not do

• Choose the tip for you, look up a sales-tax rate, or figure a loan payment. You pick the percent. The page only does the arithmetic.
• Decide whether a discount is a good price. It only does the arithmetic.
• Store the numbers. Reload the page and the boxes are empty.

Questions

Is this percentage calculator free?

Yes. There is no account. Type the numbers and read the answer.

Does the site store what I type?

No. The answer is calculated on your device. The server sees that a browser opened this page. It does not receive the numbers in the boxes.

Why is a result a long decimal?

Some divisions do not land on a short decimal. One divided by 3 is 0.333… and the page rounds the shown result to eight decimal places. The line under the answer is the operation, so you can check it with a pencil.

Can I type a comma or a percent sign?

Yes. 1,000 is read as 1000. A percent sign at the end of a box is ignored. A space in the middle of a number is not a number.

What is the difference between percent of and percent off?

Percent of tells you the share itself. 20% of 50 is 10. Percent off tells you what remains after that share is removed. 20% off 50 is 40.

How does the tip work?

Pick “What tip should I leave on a bill?” Type the bill total in the first box and the tip percent in the second, or tap 15%, 18%, 20%, or 25%. The large number is the tip. The sentence under it is the total. Set “People sharing the bill” above 1 to divide that total. Each share is rounded to the nearest cent, so the shares can miss the total by a cent.

Can the answer be negative?

Yes. A negative percent of a positive number is negative. A change from 50 to 40 is a decrease, and the page says decrease rather than showing a minus sign in the big result.