Math & Numbers Calculators
Thirteen calculators for the arithmetic and algebra that comes up in real life and in coursework — each one shows the steps, not just the answer.
Start with percentages — they underpin everything else
More people search for percentage maths than any other calculation, and for good reason: discounts, interest, tax, tips, grades and statistics are all percentages wearing different clothes. The Percentage Calculator handles all four of the common questions — what is X% of Y, X is what percent of Y, percentage increase, and percentage decrease — which between them cover almost every real-world case. If you are working with parts of a whole rather than hundredths, the Fraction Calculator and the Ratio Calculator are the same idea in a different notation.
Averages are the easiest number to misread
The Average Calculator returns mean, median and mode together, deliberately. The mean is what people call "the average", but it is dragged around by outliers — one very high salary lifts a team's mean pay while the median stays put. The median is the middle value and the more honest summary of skewed data; the mode is the most common value and the only one that works for categories. Reading all three at once is the fastest way to notice that a dataset is not behaving like you assumed.
Algebra tools that show the steps
The Algebra Calculator solves linear equations for x and lays out each rearrangement, so it works as a check on your own working rather than a replacement for it. The Quadratic Equation goes further: it returns the roots, the discriminant and the vertex, which together tell you not just the answers but what the parabola is doing — two real roots, one repeated root or none at all. For powers, roots and logarithms, the Exponents covers the index laws in one place.
Number theory and notation
The LCM & GCD finds the lowest common multiple and greatest common divisor — the pair of ideas behind adding fractions with different denominators and simplifying them afterwards. The Roman Numerals handles the other direction of notation, converting between Arabic and Roman numerals with the subtractive rules applied correctly (IV, not IIII).
Which calculator for which job
For a quick sum, the Basic Calculator takes a typed expression and respects order of operations. For trigonometry, logarithms and scientific notation, use the Scientific Calculator. If you need numbers rather than answers — for sampling, testing or games — the Random Number produces them in any range. For grade maths specifically, the tools live in our grade calculators section rather than here.