Skip to content
Allin
Sign up · Sign in

Calculator

Evaluate math expressions with parentheses, powers and modulo, live.

Related tools

All Numbers & arithmetic tools →
Amicable Number CheckerCheck whether two numbers are amicable — or give just one and get its candidate partner plus the verified loop, with perfect and sociable numbers identified.Arctan2 Calculator (atan2 of y and x)atan2(y, x) is not atan(y/x): it reads the signs of both arguments to place the angle in the right quadrant over the full −180°…180° turn, and it stays defined when x = 0. Enter x and y, read the angle in degrees or radians, see the quadrant and the point plotted. For a single ratio with no quadrant information, use the arctan calculator instead.Carry and borrow visualizerAdds or subtracts two whole numbers the way it is taught in school — set up in columns, digit by digit — and highlights every carry (addition) or borrow (subtraction) as it happens. A clear way to see the mechanic behind column arithmetic.Ceiling and floor function calculatorThe ceiling ⌈x⌉ rounds up to the next integer, the floor ⌊x⌋ rounds down. Enter any number to get both, plus the ordinary round, the truncation toward zero and the fractional part left over.Common Factor CalculatorFind every common factor of 2 to 10 numbers, with the greatest common factor highlighted and coprime pairs flagged.Comparing fractions calculatorWhich fraction is bigger? Enter two and it cross-multiplies to compare them exactly — no rounding — and shows both as decimals so you can see how close they are.Continued fraction calculatorExpand a number into its continued fraction [a₀; a₁, a₂, …] and list the convergents — the best rational approximations at each step. Feed it a decimal, an exact fraction a/b, or a square root √k: rationals terminate, √k is periodic, and irrationals stream on to the term cap. Continued fractions give the closest fractions for a given size of denominator and reveal the hidden structure of numbers like the golden ratio and π.Cube calculatorCompute the volume and surface area of a cube from its side length.

Open Calculator and you get an answer straight away, with no account to create. You will find it under Numbers & arithmetic, with Amicable Number Checker and Arctan2 Calculator (atan2 of y and x) for the neighbouring cases.

How to use it

  1. Open the tool — no signup or install needed.
  2. Enter your input or adjust the available options.
  3. Get your result instantly, then copy or download it.

Frequently asked questions

What is Calculator?

Evaluate math expressions with parentheses, powers and modulo, live.

When would I actually use this?

Reading a number written another way: a Roman numeral on a monument, a hexadecimal colour, a binary byte, or a fraction that needs reducing.

What is the most common mistake?

Assuming a decimal fraction survives a change of base. A tenth is exact in decimal and infinitely repeating in binary, which is why 0.1 + 0.2 is not 0.3 in most programming languages.

What else is filed next to it?

Amicable Number Checker, Arctan2 Calculator (atan2 of y and x) and Carry and borrow visualizer share its section. They are not variants of it — being filed together is not the same as being alike — but that is where to look if this turned out not to be the tool you wanted.

Where do the figures come from?

Base conversion and number-theory results are exact. Roman numerals follow the standard subtractive form used since the Middle Ages, which is not the only one the Romans themselves used.

Further reading

All guides →
How-toHow to Round Numbers: Round Half Up, Round Half to Even, and MoreRound to any decimal place or number of significant figures, and learn when to use round half up versus round half to even to avoid bias.ExplainerSignificant Figures Explained: Counting, Rounding, and Why They MatterLearn what counts as a significant figure, the rules for leading, trailing, and captive zeros, and how sig figs keep your calculated answers honest.How-toHow to Find Prime Factors: Factor Trees and the Division MethodBreak any whole number into its prime building blocks with a factor tree or repeated division — and write the result as a clean prime factorization with exponents.How-toHow to Multiply and Divide Fractions: Multiply Across, Flip to DivideMultiplying fractions needs no common denominator — just multiply across. Dividing means multiplying by the reciprocal. Learn both with worked examples and how to simplify.How-toHow to Add and Subtract Fractions: Common Denominator, Combine, SimplifyYou can only add or subtract fractions that share a denominator. Learn to find a common denominator, combine the numerators, and simplify the result, with a worked example.How-toHow to Do Long Division: Divide, Multiply, Subtract, Bring DownLong division breaks a big division into a repeating four-step cycle. Learn the divide-multiply-subtract-bring-down loop and how to read the remainder, with a worked example.