Calculatorby CodingMarble
All calculators

Math Calculators

Percentage, fraction, scientific, statistics and geometry calculators with step-by-step answers.

Percentage CalculatorX% of Y, percentage of marks, % increase and decreasePercentage Change CalculatorPercentage increase or decrease between two numbersScientific CalculatorTrig, log, powers, roots and factorial with historyFraction CalculatorAdd, subtract, multiply, divide fractions and mixed numbersAverage CalculatorMean, median, mode and weighted average of any listStandard Deviation CalculatorSample and population SD, variance and mean with stepsRatio CalculatorSimplify ratios, solve proportions, split amountsLCM and GCD CalculatorLCM and GCD/HCF of any numbers with factor stepsQuadratic Equation CalculatorSolve ax² + bx + c = 0 with steps, discriminant and vertex.Area CalculatorArea of any shape or plot in sq ft, sq m, acres and hectares.Volume CalculatorVolume of tanks, boxes and solids in litres, m³ and cubic feet.Pythagorean Theorem CalculatorFind the hypotenuse or a missing side of a right triangle.Square Root CalculatorSquare, cube and nth roots with simplified radical form.Exponent CalculatorWork out xʸ for any base and power, with steps.Log CalculatorLogarithm in base 10, e, 2 or any base, plus antilog.Prime Number CalculatorCheck primes, factorise numbers and list primes in a range.Speed Distance Time CalculatorSolve for speed, distance or time in km/h, mph, m/s or knots.

Maths tools, sorted by the question you are asking

Maths calculators are easy to get wrong in a way that still looks right: the arithmetic is fine, but the formula answered a slightly different question. These notes are mostly about choosing correctly and reading the output, since the computation itself is the easy part.

Percentages

Two separate questions hide behind the word percentage. "What is 18% of 4,500?" and "4,500 went up to 5,310, by what percent?" need different tools. Use the percentage calculator for the first and the percentage change calculator for the second.

One trap worth internalising: a fall of 50% followed by a rise of 50% does not return you to the start, because the second percentage is taken from a smaller base. A 200 price that drops to 100 needs a 100% rise to recover. Percentage points and percentages are also different things — a rate moving from 4% to 6% is a two point move and a fifty percent increase.

Everyday number work

The scientific calculator covers trigonometry, powers and parentheses when you need a working surface rather than a single formula. For specific jobs: the fraction calculator adds and simplifies fractions without converting to decimals and losing exactness, the ratio calculator scales recipes and mixes, the LCM and GCD calculator finds common multiples and divisors, and the Roman numeral converter handles dates on monuments and chapter headings.

Statistics: the choice that changes your answer

The average calculator gives mean, median and mode together on purpose. The mean is pulled hard by outliers; the median is not. For income, house prices or response times, the median usually describes a typical case better, and quoting the mean alone can be genuinely misleading.

The standard deviation calculator asks whether your numbers are a sample or a whole population, and that choice is not cosmetic:

ChooseWhenDivides by
PopulationYou have every member of the group — all 30 students in the classn
SampleYou measured a subset and want to describe the larger groupn − 1

The sample version always returns the slightly larger figure, because a subset underestimates the spread of the whole. With large data sets the two barely differ; with ten values the gap is noticeable. If a textbook answer does not match yours, this setting is the first thing to check.

Algebra, roots and powers

The quadratic equation calculator solves ax² + bx + c = 0 and shows the discriminant, which tells you the shape of the answer before you read it: positive means two real roots, zero means one repeated root, negative means the roots are complex and the curve never touches the x-axis. The square root calculator, exponent calculator and log calculator handle the inverse pairs — remember that log and exponent undo each other, and that a logarithm's base matters, since log base 10 and natural log give different numbers for the same input. The prime number calculator tests primality and factorises.

Shapes and motion

The area calculator and volume calculator cover the standard shapes; the usual error is mixing units, measuring in centimetres and reading the result as metres. Keep every input in one unit. The Pythagorean theorem calculator finds a missing side of a right triangle and only works when the triangle actually has a right angle. The speed, distance and time calculator solves for any one of the three given the other two, and reports average speed — not the speed you held at any particular moment.

All 17 math tools on CodingMarble Calculator are free, need no sign-up and work on mobile: Percentage Calculator, Percentage Change Calculator, Scientific Calculator, Fraction Calculator, Average Calculator, Standard Deviation Calculator, Ratio Calculator, LCM and GCD Calculator, Quadratic Equation Calculator, Area Calculator, Volume Calculator, Pythagorean Theorem Calculator, Square Root Calculator, Exponent Calculator, Log Calculator, Prime Number Calculator, Speed Distance Time Calculator.

Last reviewed 2026-10-14 · How we check every calculator

Designed & built with care by This calculator site, LovePDF, LoveImage, QR Code Generator, BioData, Typing Test, Kids Learning Games, Workout Planner, Yoga at Home and Learn are made in India by the CodingMarble team — websites, web apps and SEO-first tools.Visit CodingMarble