Percentage Calculator
Pick the type of percentage problem you're solving below, and this percent calculator outputs the exact answer instantly.
About
About Percentage Calculator
Percentage literally means "per hundred," so any percentage problem, finding what percent one number is of another, calculating a discount, measuring growth, ultimately comes down to the same core relationship between a part and a whole. A percentage calculator automates that math instantly, and this percent calculator covers the handful of different percentage problem types people actually run into.
The basic formula is simple, divide the part by the whole and multiply by 100, but the problem variations are where mental math starts breaking down, especially reverse percentages, like working out what the original price was before a discount was applied. A calculator built around the specific problem type you're solving removes that friction entirely.
It's also worth knowing the difference between a percentage decrease and a percentage point difference, since they get confused constantly in news and financial reporting. If an interest rate moves from 5% to 7%, that's a 2 percentage point increase, but it's actually a 40% relative increase in the rate itself, two genuinely different numbers describing the same change.
Pick the specific problem you're solving, finding a percentage of a number, calculating percentage change, or working out a discount, and enter your figures. The calculator outputs the precise result immediately, with enough decimal precision for financial or scientific use.
If you're calculating a retail discount, the tool shows both the amount saved and the final price together, so you're not running a second calculation just to see what you'd actually pay. All the math happens locally, so whatever numbers you're working with, financial figures, test scores, stay private.
FAQ
Frequently asked questions
What does "percentage" actually mean?
It comes from Latin for "per hundred," expressing a number as a fraction out of 100. Fifty percent, for instance, is mathematically identical to fifty out of a hundred, or one half.
How do I calculate a percentage by hand?
Divide the part by the total, then multiply by 100. Scoring eight out of ten on a quiz, for example: eight divided by ten gives 0.8, multiplied by 100 gives 80 percent.
What's a percentage difference, specifically?
It's a way of comparing two values relative to their average, commonly used in science and statistics when comparing two measurements where neither one is clearly the "original" baseline value.
Can this calculate a percentage decrease, like a markdown?
Yes, there's a dedicated mode for percentage change. Enter an original value of 100 and a new value of 80, for instance, and it calculates the 20 percent decrease automatically.
Does the calculator round the result, or show full precision?
It calculates out to several decimal places for accuracy, particularly useful for financial or scientific contexts, and you can round the figure yourself afterward depending on what you actually need.
Are the numbers I calculate logged anywhere?
No, every calculation happens client-side in your browser. Financial figures, test scores, or anything else you enter stay entirely private.
Related tools
View all calculators tools →Currency Converter
Convert between world currencies using live exchange rates.
Open toolGPA Calculator
Calculate your GPA or CGPA with weighted credits and your own grading scale.
Open toolProfit Margin Calculator
Calculate gross profit margin and markup from cost and sale price.
Open toolGrade Percentage Calculator
Calculate a percentage and letter grade from marks obtained and total marks.
Open tool