Calculate percentages, percentage increase and decrease, and what percent one number is of another — with the formula shown for every result.
The Percentage Calculator handles the everyday percentage questions people search for: what is X percent of Y, what percentage increase or decrease happened between two numbers, and what percent one number represents of another. Each result shows the underlying formula, so you can see exactly how the answer was reached rather than just getting a bare number.
It runs instantly in the browser as you type, with separate modes for straightforward percentage-of calculations and percentage change calculations. This makes it useful for quick everyday maths such as working out a tip, a pay rise, or how much a price has grown or shrunk, without needing to remember or rearrange the formulas yourself.
Rather than a black-box result, each calculation displays the formula used, such as (new - old) / old x 100 for percentage change, so you can learn the method or double-check the maths by hand.
Percentage of a value, percentage increase, percentage decrease, and what-percent-is-X-of-Y are all handled in one tool, avoiding the need to search for a separate calculator for each variant.
Results update as you type with no submit button or account required, which suits quick checks while shopping, budgeting or doing homework.
Percentage change is calculated as (new value - old value) divided by the old value, multiplied by 100. Going from 80 to 100 gives (100-80)/80 x 100, which is 25% increase; a fall from 100 to 80 gives -20%, showing that increase and decrease percentages between the same two numbers are not simple mirror images.
If you know the discounted price and the discount percentage, divide the discounted price by (1 minus the discount as a decimal). A £75 sale price after a 25% discount means the original price was £75 / 0.75, which equals £100.
A common error is applying a percentage change to the wrong base number, for example calculating a decrease using the new value instead of the original. Always divide the difference by the starting value, not the ending value, to get a correct percentage change.
Subtract the old value from the new one, divide by the old value and multiply by 100. From 80 to 100 is (100-80)/80 x 100 = 25% increase.
Divide the sale price by (1 minus the discount as a decimal). A 30% discount at $70 means 70 / 0.7 = $100 original price.
Yes. Percentage Calculator on Klipza is completely free with no account, no subscription and no watermark on your files, and there is no daily usage limit.
Processing happens locally in your browser wherever technically possible, so your files are not uploaded to a server, stored or shared with third parties.
Yes. It is fully responsive and runs in any modern browser on Android, iPhone, iPad, Windows and macOS — nothing to install.