Maths calculators: percentages and percentage change, fractions, greatest common divisor, Roman numerals, quadratic equations, circle and triangle area, averages, primes, factorials, proportions, powers and number bases. All of them show the working, not only the answer.
These calculators cite nothing, deliberately. A citation vouches for a number that came from an outside source and could change; division and percentages do not change, and citing Wikipedia for percentages would only make every other citation on this site count for less.
The percentage calculator answers all three questions people actually ask: what is X% of a number, what percentage one number is of another, and by what percentage a number changed. They are three different calculations, and mixing them up is the most common mistake.
Pupils checking homework, and anyone who needs percentages, fractions or proportions in ordinary life. Every result also shows the steps, so it can be learned from rather than just copied. No sign-up and no charge.
Because arithmetic has no authority to confirm it. A percentage formula is not a VID rate that can change — it is the same in every country and every year. These pages carry only the date the wording was last read through, shown deliberately unlike the green verified chip.
If a rate goes from 20% to 25%, that is a rise of five percentage points but of twenty-five percent. News reports conflate the two almost every time, which is why the percentage change calculator shows both numbers separately.
Yes — every page has a section under the result with the steps: the discriminant and both roots for a quadratic, the common denominator and the reduction for fractions, the formula used for percentages. That part is what separates learning from copying.
Page updated 20/08/2026