Math Calculators
Everyday and school math, worked step by step. Add and simplify fractions, find a percentage, round to any place, factor a number or check a long division — every answer comes with the method behind it.
88 calculators
Most used
- Basic CalculatorA simple four-function calculator with memory, percent and square root keys, keyboard support and a paper tape that keeps every calculation.
- Fraction CalculatorAdd, subtract, multiply or divide two fractions or mixed numbers and get a simplified answer with the steps.
- Long Division CalculatorWork any whole-number division by long division, with the quotient, the remainder, the complete written layout and every divide–multiply–subtract–bring down step.
- Percent Error CalculatorCompare an experimental measurement with the accepted value and get the percent error, signed or absolute, with the work shown.
- Percentage CalculatorFind a percentage of a number, work out what percent one value is of another, or measure a percent increase or decrease.
- Percentage Change CalculatorMeasure how much a value moved from an old number to a new one, with a plus or minus sign that tells you which way it went.
Basic & long arithmetic 15
- Adding & Subtracting IntegersAdd or subtract two integers, see which sign rule applies at each step, and watch the move on a number line.
- Basic CalculatorA simple four-function calculator with memory, percent and square root keys, keyboard support and a paper tape that keeps every calculation.
- Diamond Problem SolverFill in any diamond problem — find the two side numbers from the product and sum, or the top and bottom from the sides — with factor pairs and a diagram.
- Lattice Multiplication CalculatorDraw the lattice grid for any two whole numbers, fill each box with a digit product and add along the diagonals to read off the answer.
- Long Addition CalculatorAdd up to 12 whole numbers or decimals the way you would on paper, with the column layout, every carry and a column-by-column explanation.
- Long Division CalculatorWork any whole-number division by long division, with the quotient, the remainder, the complete written layout and every divide–multiply–subtract–bring down step.
- Long Division with DecimalsDivide decimals or whole numbers to as many decimal places as you need, with the written layout, repeating-decimal detection and correct rounding.
- Long Multiplication CalculatorMultiply two numbers with the standard paper method, showing each partial product, the carries, the placeholder zeros and where the decimal point goes.
- Long Subtraction CalculatorSubtract whole numbers or decimals in a column layout that shows every borrow, including tricky borrowing across zeros, with each step explained.
- Money Math CalculatorAdd, subtract, multiply or divide dollar amounts with exact arithmetic and correct rounding to the cent, including fair splits that add back to the total.
- Multiplication TablePrint any times table or a full 12 × 12 chart, and practice the facts with a self-checking quiz that marks each answer as you type.
- Order of Operations (PEMDAS)Type an arithmetic expression and watch it simplify one operation at a time in PEMDAS order, with each rule named and highlighted.
- Reciprocal CalculatorFind the reciprocal of any number — whole, decimal, fraction, mixed or repeating — as an exact fraction, a mixed number and a decimal.
- Scientific CalculatorEvaluate full expressions with trig functions, logarithms, powers, roots and factorials, in degrees or radians, with a history tape you can reuse.
- Speed Distance Time CalculatorFind speed, distance or travel time from the other two values, in the units you use, with results converted to mph, km/h, m/s and more.
Fractions 21
- Adding & Subtracting FractionsAdd and subtract up to six fractions or mixed numbers in one go, with the least common denominator, the rewritten fractions and the simplified answer.
- Average of Fractions CalculatorFind the exact mean of a list of fractions, mixed numbers and decimals by adding over a common denominator and dividing by how many there are.
- Comparing Fractions CalculatorFind out which of two fractions is larger with cross-multiplication, a common denominator, decimals and side-by-side fraction bars.
- Complex Fractions CalculatorCombine two complex fractions — fractions whose top and bottom are fractions — with any of the four operations, simplifying each one first.
- Decimal to Fraction CalculatorConvert terminating or repeating decimals to simplified fractions and mixed numbers, with the place-value or algebra method shown step by step.
- Equivalent Fractions CalculatorList fractions equal to a given fraction, reduce it to simplest form, or find the equivalent fraction with the denominator you need.
- Estimating Fractions CalculatorEstimate a fraction sum or difference by rounding each fraction to 0, 1/2 or 1, then check the estimate against the exact answer.
- Fraction CalculatorAdd, subtract, multiply or divide two fractions or mixed numbers and get a simplified answer with the steps.
- Fraction Exponents CalculatorEvaluate (a/b)^(c/d) — a fraction raised to a fractional, negative or whole-number power — with root-then-power steps and an exact answer when it exists.
- Fraction to Decimal CalculatorConvert a fraction or mixed number to a decimal by long division, with repeating digits marked, a rounding option and the division layout.
- Fraction to Decimal ChartAn interactive chart of fractions with their decimal and percent equivalents, from halves to 64ths, including inch fractions in millimeters.
- Fractions on a Number LineDraw number lines marked in any denominator from 2 to 16, compare two lines side by side, and plot a fraction or mixed number to see where it lands.
- Improper Fraction to Mixed NumberTurn an improper fraction into a mixed number by dividing, with the quotient as the whole part and the remainder over the denominator.
- Mixed Number to DecimalTurn a mixed number into a decimal by dividing the fraction part and adding the whole number, with repeating digits marked and rounding options.
- Mixed Number to Improper FractionTurn a mixed number into an improper fraction by multiplying, adding and keeping the denominator, then reduce it to lowest terms.
- Mixed Number to PercentTurn a mixed number into a percent — 1 3/4 becomes 175% — with the decimal and fraction methods shown and repeating digits handled.
- Mixed Numbers CalculatorAdd, subtract, multiply or divide two mixed numbers and get a simplified mixed-number answer, with the improper-fraction method and regrouping explained.
- Ordering Fractions CalculatorSort a list of fractions, mixed numbers and decimals from least to greatest or greatest to least, using a common denominator with every step shown.
- Simplifying Complex Fractions CalculatorReduce a complex fraction — even one with sums or differences on top and bottom — to a single simplified fraction using two methods.
- Simplifying Fractions CalculatorReduce a fraction or mixed number to lowest terms by finding the greatest common factor, with Euclid's algorithm and a prime-factor check shown.
- Solve for X in Fractions CalculatorSolve a proportion a/b = c/d for an unknown in any of the four positions, with cross-multiplication, an exact fraction answer and a check.
Percentages 13
- Average Percentage CalculatorCombine percentages from groups of different sizes into one correct overall percentage, and see how it differs from a simple average.
- Decimal to Percent CalculatorTurn a decimal into a percent by multiplying by 100, with the decimal-point shift shown and an optional rounded answer.
- Fraction to Percent CalculatorChange a fraction or mixed number into a percent, with the exact repeating form, a rounded answer and the method shown.
- Percent Error CalculatorCompare an experimental measurement with the accepted value and get the percent error, signed or absolute, with the work shown.
- Percent of a Percent CalculatorTake a percentage of a percentage, find what percent one percentage is of another, or combine several percentage changes into one.
- Percent to Decimal CalculatorChange any percent into the decimal you need for formulas, including fractional percents and repeating results.
- Percent to Fraction CalculatorWrite any percent as a simplified fraction or mixed number, with the steps for clearing decimals and reducing by the GCF.
- Percent Tolerance CalculatorGet the allowed minimum and maximum for any nominal value and tolerance, then check whether a measured part or reading is in spec.
- Percentage CalculatorFind a percentage of a number, work out what percent one value is of another, or measure a percent increase or decrease.
- Percentage Change CalculatorMeasure how much a value moved from an old number to a new one, with a plus or minus sign that tells you which way it went.
- Percentage Decrease CalculatorWork out how much something dropped in percent, what's left after a percentage comes off, or what it cost before the markdown.
- Percentage Difference CalculatorCompare two numbers when neither one is the starting point, using their average as the reference so the order doesn't matter.
- Percentage Increase CalculatorFind the percent increase between two numbers, raise a number by a percentage, or undo an increase to recover the original value.
Ratios & rates 7
- Cross Multiplication CalculatorSolve proportions with x in the numerators or denominators by cross-multiplying, or compare two fractions using their cross products.
- Golden Ratio CalculatorDivide a length into golden-ratio parts or size a golden rectangle from any one measurement, using φ ≈ 1.618034.
- Proportion CalculatorSolve direct, inverse and square-law proportion problems, find the constant of proportionality, or test whether a table is proportional.
- Ratio CalculatorFind the missing number in a proportion, resize a ratio by a factor or target, or share a total among parts in a fixed ratio.
- Ratio SimplifierReduce a two- or three-part ratio to its simplest whole-number form, even when the terms are decimals or fractions.
- Ratio to Fraction CalculatorTurn a ratio into part-to-whole and part-to-part fractions, with percentages and a bar model that shows how the whole is divided.
- Unit Rate CalculatorReduce any rate to "per one" — miles per hour, cost per ounce — or compare package prices to find the best value.
Rounding & significant figures 6
- Round to Nearest MultipleRound a number to the nearest multiple of any step — 5, 12, 0.25, 0.05 — or force it up or down, with a number line.
- Rounding CalculatorRound a number to any place value, from millions down to millionths, and see which digit decided the result.
- Rounding Methods CalculatorSee how ten different rounding rules treat the same number, including ties like 2.5 and negative values, with the rule for each explained.
- Round to Sig FigsRound a number to a chosen count of significant figures and get a result that shows its precision clearly, in standard and scientific form.
- Significant Figures CalculatorDo arithmetic with measurements and get an answer rounded to the right number of significant figures, with the rule that set it.
- Significant Figures CounterPaste a measurement and see how many significant figures it has, with every digit highlighted and the rule that applies to it.
Factors, multiples & primes 11
- Common Factors CalculatorSee all the factors your numbers share, side by side with each number's full factor list, and the GCF that ties them together.
- Euclid's Algorithm CalculatorFind the greatest common divisor of two whole numbers with Euclid's repeated-division method, including the extended version.
- Factors CalculatorFind all the factors and factor pairs of any whole number, plus whether it's prime or composite and how its factors add up.
- GCF CalculatorFind the largest number that divides every number in a list, using the method your class teaches, with each step written out.
- LCD CalculatorFind the smallest denominator a set of fractions can share, then see every fraction rewritten over it, ready to add or compare.
- LCM CalculatorFind the smallest number that every number in your list divides into, with prime-factor, GCF or listing steps.
- Prime Numbers ListList all the prime numbers between two values, with counts, twin primes and gaps, and see how the Sieve of Eratosthenes finds them.
- Modulo CalculatorFind the remainder of a division (a mod n) under every common convention, including how negatives behave in different programming languages.
- Multiples CalculatorGenerate the multiples of any number, find the ones between two values, or test whether a number is a multiple — with the quotient shown.
- Prime Factorization CalculatorWrite any whole number as a product of primes, with a drawn factor tree, the division ladder and the exponent form.
- Prime Number CheckerFind out whether a number is prime or composite, see what divides it, and get the nearest primes on either side.
Number notation & place value 6
- Expanded Form CalculatorBreak a number into the value of each digit, in four expanded-form styles, for whole numbers and decimals alike.
- Place Value CalculatorPut any number on a place value chart, find the place of a chosen digit and see what every digit is worth.
- Scientific Notation CalculatorDo arithmetic with numbers written as a × 10ⁿ and get a normalized answer, with every coefficient and exponent step shown.
- Scientific Notation ConverterRewrite a number in scientific, E-, engineering and SI-prefix notation, or turn notation back into a plain decimal, with the decimal-point moves explained.
- Standard Form CalculatorTurn scientific notation, E-notation or expanded form into standard form, whichever meaning your class uses — ordinary digits or a × 10ⁿ.
- Word Form to Standard FormTurn a number written in English words into digits, or write digits out in words, with each period explained.
Number properties & sequences 4
- Collatz Sequence CalculatorFollow the 3n + 1 rule from any starting number, count the steps to reach 1, find the peak value and chart the hailstone path.
- Digit Sum CalculatorAdd up the digits of a number, repeat to find its digital root, and see the alternating digit sum, digit product and digit frequencies.
- Divisibility Rules CheckerCheck a whole number against the divisibility rules for 2 to 13, see each rule worked out on your number, and test any extra divisor.
- Perfect Number CheckerClassify any whole number as perfect, abundant or deficient from the sum of its proper divisors, or survey every number up to N.
Word problems 5
- Addition & Multiplication ProblemsPractice deciding when to add and when to multiply, with fresh grade 2–5 word problems and solutions that show the arithmetic.
- Age Word ProblemsGenerate new age word problems at three difficulty levels, from sums and ratios to past and future multiples, each with a full algebra solution.
- Coin Word ProblemsGenerate fresh coin word problems at three difficulty levels and check each one against a step-by-step algebra solution.
- Division Word ProblemsPractice division word problems for grades 3–6, including when to round a remainder up, drop it or report it, with full solutions.
- Percentage Change Word ProblemsGenerate real-world percent change problems — raises, discounts, population changes, reverse percentages — and check your work against a full solution.
Number reference
Guides
- How to Add and Subtract Fractions With Unlike DenominatorsRewrite both fractions over a common denominator, then add or subtract the numerators. Step-by-step method, shortcuts and mixed-number examples.
- How to Calculate a Percentage: 3 Formulas With ExamplesEvery percentage problem is one of three questions about a part, a whole and a rate. Learn the formula for each, plus fast mental shortcuts.
- How to Calculate Percentage Change, Increase and DecreaseOne formula covers every percentage increase and decrease. Learn it, plus how to reverse a change, chain several changes and avoid the classic traps.
- How to Convert a Decimal to a Fraction (Including Repeating Decimals)Write the decimal over a power of 10 and simplify, or use a short algebra trick for repeating decimals. Includes an inch-fraction chart.
- How to Do Long Division: Step-by-Step With ExamplesLong division is one four-step cycle repeated: divide, multiply, subtract, bring down. Worked examples cover remainders, two-digit divisors and decimals.
- How to Find the GCF and LCM: 4 Methods and When to Use EachFour ways to find the greatest common factor and least common multiple, the shortcut that links them, and how to tell which one a word problem is asking for.
- How to Simplify Fractions: 3 Methods and Common MistakesReduce any fraction to lowest terms by dividing the top and bottom by their greatest common factor. Three methods, divisibility shortcuts and worked examples.
- How to Write Numbers in Scientific Notation (and Calculate With Them)Write any number as a value from 1 to 10 times a power of ten, convert back, and do arithmetic in scientific notation without losing track of the exponent.
- Order of Operations (PEMDAS) Explained With ExamplesPEMDAS tells you which part of an expression to calculate first. Learn the rules, the left-to-right tie-breaker and the traps that cause most errors.
- Significant Figures Rules: Counting, Rounding and CalculatingWhich digits count as significant, how to round to a given number of sig figs, and how many to keep after adding, multiplying or taking a logarithm.