FinanzTool

Percentage Calculator

Last reviewed: 2026-09-22

Add or subtract a percentage from any number, or find out what percentage one number is of another — results appear instantly as you type, no sign-up needed.

Calculator

Increase or decrease by a percentage

Increased value 220.00 Change: +20.00
Decreased value 180.00 Change: −20.00

What percentage is one number of another?

As a percentage of the total 12.50%

How it's calculated

Both calculators use simple, standard percentage formulas — nothing hidden.

Increase or decrease by a percentage

The change is: Number × Percentage ÷ 100. Add that change to get the increased value, or subtract it to get the decreased value.

Finding what percentage one number is of another

Divide the first number by the second, then multiply by 100: (Number ÷ Total) × 100.

Worked example

Suppose a value of 200 increases by 10%. The change is 200 × 10 ÷ 100 = 20, so the increased value is 200 + 20 = 220, and the decreased value would be 200 − 20 = 180.

Now suppose you scored 25 points out of a possible 200. As a percentage: (25 ÷ 200) × 100 = 12.5%.

Frequently asked questions

How is the increased or decreased value calculated?

We multiply your number by the percentage and divide by 100 to get the change, then add or subtract that change from the original number. For example, 10% of 200 is 20, so 200 plus 10% is 220, and 200 minus 10% is 180.

How do I find out what percentage one number is of another?

Divide the first number by the second, then multiply by 100. For example, to find out what percentage 25 is of 200: (25 ÷ 200) × 100 = 12.5%.

Can I use negative numbers or percentages?

Yes — the calculator also works with negative numbers and negative percentages, for example to calculate a discount or a loss.

For information only. Not financial or tax advice.