Math

Math and science calculators for school, work and everyday problem solving: percentages, averages, fractions, geometry, statistics, physics formulas and unit conversions between bases. Every answer shows the formula and the working, so you can check it.

222 free tools in this category. See every tool on Lelifi.

• 0.125 as a Fraction0.125 as a fraction is 125/1000, which cancels to 1/8. See the slot weights, the
• 0.2 as a Fraction0.2 as a fraction is 2/10, which shrinks to 1/5. See the tenths column, the 20 p
• 0.25 as a Fraction0.25 as a fraction is 25/100, which cuts to 1/4. See the hundredths column, the
• 0.375 as a Fraction0.375 as a fraction is 375/1000, which strips to 3/8. See Euclid's divisions, th
• 1/10 as a Decimal1/10 is 0.1 as a decimal and 10 percent. See the long division, the place value,
• 1/10 as a Percent1/10 as a percent is 10 percent. See the division step, a tenths conversion tabl
• 1/16 as a Decimal1/16 as a decimal is 0.0625, the shortest mark on a standard inch ruler. See the
• 1/16 as a Percent1/16 as a percent is 6.25 percent. See the division, a sixteenths table, price a
• 1/5 as a Decimal1/5 is 0.2 as a decimal and 20 percent. See the long division, the fifths table,
• 1/6 as a Decimal1/6 as a decimal is 0.1666 with the 6 repeating. See the long division, a sixths
• 1/6 as a Percent1/6 is 16.67 percent, rounded from 16.666... See the long division, a rounding t
• 1/7 as a Decimal1/7 as a decimal is 0.142857, and the six digits repeat forever. See the long di
• 1/8 as a Decimal1/8 as a decimal is 0.125, a terminating decimal because 8 is a power of 2. See
• 1/8 as a Percent1/8 as a percent is 12.5 percent. See the three steps, an eighths table, what 12
• 1/9 as a Decimal1/9 as a decimal is 0.111... with the 1 repeating forever. See the long division
• 1/9 as a Percent1/9 as a percent is 11.11%, rounded from 11.1111... percent. See the division, t
• 11/16 as a Decimal11/16 as a decimal is 0.6875, exact in four digits. See the long division, the s
• 13/16 as a Decimal13/16 as a decimal is 0.8125, an exact four place decimal. See the long division
• 15/16 as a Decimal15/16 as a decimal is 0.9375, an exact four place answer. See the long division,
• 18 Electron Rule CalculatorPick a metal, set its oxidation state and ligands, and get the d electron count
• 2 Sample Z Test CalculatorFree 2 sample z test calculator. Enter two means, standard deviations and sample
• 2/5 as a Decimal2/5 as a decimal is 0.4, a decimal that stops. See the one step division, the fi
• 2/5 as a Percent2/5 as a percent is 40%, an exact conversion with no rounding. See the division,
• 2/7 as a Decimal2/7 as a decimal is 0.285714 with the six digits repeating forever. See the long
• 2/7 as a Percent2/7 as a percent is 28.57%, rounded from 28.571428 percent. See the division, th
• 2/9 as a Decimal2/9 as a decimal is 0.2222 repeating, written 0.2 with a bar. See the division,
• 2/9 as a Percent2/9 as a percent is 22.22%. See the division, the repeating decimal 0.222..., tw
• 30-60-90 Triangle CalculatorSolve any 30-60-90 triangle from one known side. Enter the short leg, long leg o
• 45-45-90 Triangle CalculatorSolve any 45-45-90 right triangle from one side. Enter a leg or the hypotenuse a
• Absolute Change CalculatorMeasure the change between two numbers with the new minus old rule. Get the sign
• Absolute Value CalculatorFind the absolute value of a number, the distance between two points, or both so
• Acceleration CalculatorEnter two speeds and a time, a distance and a time, or a force and mass to get a
• Angle Between Two Vectors CalculatorFind the angle between two 2D or 3D vectors. The calculator returns the dot prod
• Angular Acceleration CalculatorEnter two spin rates and a time, or an angle and a time, to get angular accelera
• Angular Velocity CalculatorConvert rpm to rad/s and back, get turns per second and period, and turn spin in
• Arc Length CalculatorEnter a radius and a central angle to get the arc length, the chord, the sector
• Arcsin CalculatorGet the angle behind any sine value from -1 to 1 in degrees and radians, or solv
• Arctan CalculatorFind the angle behind a tangent value in degrees and radians, turn rise and run
• Arctan: Series, Identities and Exact ValuesArctan beyond the button: the Gregory series, the 90 degree complement identity,
• Area of a Sector CalculatorEnter a radius and a central angle in degrees or radians to get the sector area,
• Atoms to Moles CalculatorConvert a particle count to moles or moles to atoms with the exact Avogadro cons
• Average CalculatorPaste a list of numbers to get the mean, median, sum, count, range and a weighte
• Average Percentage CalculatorAverage a list of percentages, then add group sizes to get the weighted average
• Average Rate of Change CalculatorEnter two points and get the average rate of change between them, with the rise,
• Average Velocity CalculatorFind average velocity from distance and time in mph, km/h, m/s or ft/s, split a
• Base CalculatorConvert numbers between base 2 to 36, read place values, and add, subtract or mu
• Base ConverterConvert a number between any two bases from 2 to 36, including fractions and neg
• Batting Average CalculatorCalculate a batting average from hits and at-bats, see it as a percentage, build
• Binary CalculatorAdd, subtract, multiply or divide binary numbers and convert between binary, dec
• Binomial Coefficient CalculatorCompute C(n, k) exactly for large n, with the n choose k formula, Pascal's trian
• Binomial Distribution CalculatorFind exactly, at most and at least probabilities for n trials and a success chan
• Boolean Algebra CalculatorEvaluate Boolean expressions, build a full truth table, list minterms and maxter
• Central Limit Theorem CalculatorFind the standard error, the z-score of a sample mean and the chance of landing
• Centrifugal Force CalculatorEnter a mass, a radius and a speed or rpm to get the outward force in a rotating
• Centripetal Force CalculatorWork out the inward force that bends a car, a rider or a planet into a curve fro
• Change in Momentum CalculatorFind the change in momentum from mass and two velocities, in kg m/s or N s, and
• Characteristic Polynomial CalculatorFind the characteristic polynomial and eigenvalues of a 2x2, 3x3 or 4x4 matrix,
• Charles's Law CalculatorSolve Charles's law for any missing volume or temperature, with Kelvin conversio
• ChemistrySolve any dilution by filling in three of four values. Moles, molarity and the C
• Circle CalculatorCircle calculator: enter a radius, diameter, circumference or area and get the o
• Circumference CalculatorFind a circle's circumference from its radius, diameter, or area, or work backwa
• Circumference to Diameter CalculatorConvert any circumference to its diameter by dividing by pi, with tape error ran
• Class Width CalculatorEnter the smallest and largest values and the number of classes. Get the range,
• Coefficient of Determination CalculatorPaste paired x and y data to get R squared, the correlation r, the least squares
• Coefficient of Friction CalculatorFind the coefficient of friction from a push test or an incline angle, get the f
• Coefficient of Variation CalculatorTurn a mean and standard deviation into a coefficient of variation, compare rela
• Completing the Square CalculatorEnter a, b and c to rewrite any quadratic in completed square form, read off the
• Confidence Interval CalculatorBuild a confidence interval for a mean from raw data or a summary, for a share f
• Convolution CalculatorCompute the discrete convolution of two sequences step by step: every output, th
• Cosecant CalculatorGet csc for any angle in degrees, radians or pi form, turn a sine value or two t
• Cosine CalculatorGet cos(x) in degrees or radians, solve a triangle with the law of cosines from
• Cotangent CalculatorGet the cotangent for any angle in degrees or radians, from a tangent, sine or c
• Cross Product CalculatorEnter two 3D vectors to get the cross product components, its magnitude, the ang
• Cube Root CalculatorEnter any number to get its cube root as a decimal, plus the simplified radical
• Decimal to Fraction CalculatorConvert a decimal to a fraction in lowest terms, with mixed numbers, repeating d
• Decimal to Octal ConverterConvert decimal to octal by repeated division by 8, with a worked ladder, a char
• Decimal to Percent ConverterConvert any decimal to a percent by moving the point two places: 0.375 is 37.5 p
• Degrees of Freedom CalculatorFind degrees of freedom for t tests, chi square, ANOVA and regression. See why 2
• Dew Point CalculatorEnter air temperature and relative humidity to get the dew point in Fahrenheit a
• Dividing Exponents CalculatorDivide powers in one step: x^a over x^b equals x^(a-b). Calculator plus worked e
• Dot Product CalculatorCompute the dot product from components or from magnitudes and an angle: get mag
• Electric Field CalculatorFind the electric field from a point charge with E = k q / r squared, in N/C or
• Empirical Probability CalculatorTurn counts into an empirical probability: enter successes and trials to get the
• Empirical Rule CalculatorEnter a mean and standard deviation to get the 68, 95 and 99.7 percent bands, th
• Equation of a Line CalculatorFind the equation of a line from two points, a point and a slope, or a slope and
• Equilateral Triangle CalculatorType one side, height, area, perimeter or radius to get the rest of an equilater
• Equivalent Fractions CalculatorSimplify any fraction, list its equivalent forms, check two fractions with cross
• Escape Velocity CalculatorCalculate escape velocity from Earth, the Moon, Mars or any body, in km/s and mp
• Exponent CalculatorRaise any base to any power, including negative and fractional exponents, and se
• Exponent Rules CalculatorApply all five laws of exponents to two powers at once: product, quotient, power
• Exponential Growth CalculatorEnter a starting value, a growth rate and a number of periods to get the final v
• FPE CalculatorTurn grains and feet per second into foot-pounds of energy, get joules and momen
• Factorial CalculatorGet n factorial exactly for any whole number up to 1000, plus digit count, trail
• Factorial CalculatorFactorial calculator for any n up to 170: get the exact value of n!, the digit c
• Fibonacci CalculatorGenerate Fibonacci numbers up to F(1000) exactly, with the running sum, digit co
• Force CalculatorFind force, mass or acceleration with F = ma, in newtons, pounds-force, kilogram
• Fraction CalculatorAdd, subtract, multiply or divide two fractions, with whole numbers, and see the
• Fraction Exponent CalculatorRaise any fraction to a fractional power and get the decimal result, the exact f
• Fraction SimplifierType a fraction to reduce it to lowest terms and see the greatest common factor,
• Fraction to Decimal CalculatorConvert a fraction or mixed number to a decimal and see whether it terminates or
• Fraction to Percent CalculatorConvert any fraction or mixed number to a percent, pick the rounding, and turn a
• Frequency CalculatorCalculate frequency in hertz from cycles and time, then convert the result to pe
• Friction CalculatorGet friction force from a load and a coefficient, plus ramp hold and slide angle
• GCF CalculatorFind the greatest common factor of two or three whole numbers, with the prime fa
• Gear Ratio CalculatorEnter the tooth counts to get the gear ratio, output rpm and torque multiplicati
• Geometric Mean CalculatorMultiply n numbers, take the nth root and get the real average growth rate: retu
• Golden Ratio CalculatorEnter one length to get the golden ratio split, size a rectangle at 1.618, or ch
• Half-Life CalculatorFind the amount left after any number of half-lives, the decay constant, the tim
• Heat Index CalculatorEnter the temperature and relative humidity to get the NWS heat index, the edge
• Hex CalculatorConvert hex to decimal and binary, add, subtract, multiply or divide in base 16,
• Horizontal Projectile Motion CalculatorGet fall time, range, impact speed and landing angle for a level launch. Uses g
• IQ Percentile CalculatorTurn an IQ score into a percentile, with the z score, the share of people above
• Ideal Gas Law CalculatorSolve PV = nRT for pressure, volume, moles or temperature in any unit, with work
• Improper Integral CalculatorCheck whether an improper integral converges or diverges, see the p-test verdict
• Instantaneous Velocity CalculatorFind the velocity at one instant from two close position readings, or from v = v
• Inverse Sine CalculatorTurn any sine value from -1 to 1 into its angle in degrees and radians, get the
• Kinetic Energy CalculatorFind kinetic energy in joules from mass and speed, see it in kJ, kWh and foot-po
• LCM CalculatorFind the least common multiple of two or three numbers, with the prime factors,
• Log Base 2 CalculatorFind log base 2 of any positive number, with the change of base steps shown, the
• Log CalculatorLog calculator for any base: enter a number and a base to get log base b of x, w
• Magnitude of Acceleration CalculatorCompute the magnitude of acceleration from vector components ax, ay and az, or f
• Margin of Error CalculatorTurn a sample size and a percentage into a margin of error at 90, 95 or 99 perce
• Marks Percentage CalculatorTurn marks into a percentage for one paper or three weighted papers, see the US
• Mass Percent CalculatorFree mass percent calculator: enter the solute and solution mass to get percent
• Matrix Transpose CalculatorPaste a matrix and get its transpose instantly: rows become columns, a 2 x 3 mat
• Midpoint CalculatorFind the midpoint of two points with the coordinate sums, the distance check and
• Midrange CalculatorEnter a list of numbers to get the midrange from the lowest and highest values,
• Mixed Number CalculatorAdd, subtract, multiply or divide mixed numbers and get the answer as a mixed nu
• Molality CalculatorFind molality in mol/kg from solute mass, molar mass and solvent mass, then get
• Molarity CalculatorFind molarity from mass, volume and molar mass, work out the grams a target solu
• Mole Fraction CalculatorEnter moles or grams for each component and get the mole fraction, mole percent,
• Mole Ratio CalculatorTurn a balanced equation's coefficients into moles and grams, with mole fraction
• Momentum CalculatorFree momentum calculator: multiply mass by velocity to get momentum in kg m/s, w
• Multiplying Exponents CalculatorMultiply powers with the same base by adding exponents, including negative and f
• Multiplying Fractions CalculatorMultiply two fractions or mixed numbers and see the canceling, the product befor
• Negative Exponents CalculatorCalculate negative exponents as reciprocals, check zero and fractional powers, a
• Normal Distribution CalculatorCalculate normal distribution probabilities, z scores, percentiles, and ranges f
• Normal Force CalculatorFind the normal force on flat ground, a slope, an accelerating lift or under an
• On Base Percentage CalculatorWork out on-base percentage from hits, walks, hit-by-pitches, at-bats and sacrif
• Outlier CalculatorPaste a list of numbers to find outliers by interquartile fences, z-scores, the
• P Value CalculatorTurn a z score or a t score into a one-tailed and two-tailed p value, see the ca
• PPM CalculatorTurn milligrams per liter, milligrams per kilogram or a diluted stock into parts
• PPM ConverterConvert ppm to percent, ppb, mg/L and mg/kg, or run any of them back to ppm, wit
• Pascal's Triangle CalculatorDraw the first rows of Pascal's triangle, look up any cell C(n, k) with the work
• Percent Decrease CalculatorEnter old and new values to get the percent decrease, the dollar drop, the share
• Percent Error CalculatorCompare a measured value with an accepted value to get percent error, the signed
• Percent Off CalculatorFind the sale price and the dollars saved from any percent off, then check the p
• Percent Yield CalculatorTurn the limiting reactant into a theoretical yield in grams, then compare your
• Percent of Sales CalculatorFind what percent of sales a cost, price or profit represents, then project the
• Percent to Fraction CalculatorTurn any percent into its simplest fraction, including repeating decimals like 3
• Percentage CalculatorWork out a percent of a number, one number as a percent of another, percent chan
• Percentage Calculator and GuideLearn what a percentage is, convert decimals, fractions and percents, and solve
• Percentage Change CalculatorFind the percent change between two numbers. $24.99 to $31.49 is up 26.01%, $89
• Percentage Decrease CalculatorEnter a starting value and a lower value to see the percent decrease, the size o
• Percentage Difference CalculatorCompare pair of figures and get the percentage difference, using the midpoint of
• Percentage of a Percentage CalculatorEnter a base and two rates to get a percentage of a percentage, the combined per
• Percentile CalculatorPaste a list of numbers to get the percentile rank of any score and the value at
• Perimeter CalculatorPick a shape, enter the sides or radius, and get the perimeter in feet, meters o
• Physics CalculatorCalculate kinetic energy, momentum, distance, and an average force estimate from
• Pie Chart CalculatorEnter up to six slice values and get the percent share and central angle of ever
• Point-Slope Form CalculatorEnter a point and a slope to get the point-slope form, slope-intercept form and
• Poisson Distribution CalculatorPoisson distribution calculator: enter a rate and a count to get P(X = k), P(X a
• Polygon CalculatorRegular polygon calculator: enter the number of sides and side length for area,
• Pooled Variance CalculatorCombine two sample variances by degrees of freedom: sp^2 = ((n1-1)s1^2 + (n2-1)s
• Prime Factorization CalculatorFactor any integer up to a trillion into primes with full trial division steps,
• Probability CalculatorFind the chance of A, B, both or either, plus conditional probability, odds and
• Probability CalculatorFind the chance of A, B, both or either, plus conditional probability, odds and
• Pythagorean Theorem CalculatorSolve a right triangle from any two sides: missing side, area, perimeter, angles
• Quadratic Equation CalculatorSolve a quadratic equation to find real or complex roots, the discriminant, vert
• Quadratic Formula CalculatorSolve ax^2 + bx + c = 0 with both roots, the discriminant, the vertex and the fa
• Quartile CalculatorEnter a list of numbers to get Q1, the median, Q3, the interquartile range and a
• Ratio CalculatorSolve the missing number in A : B = C : D by cross multiplication, simplify a ra
• Ratio to Fraction CalculatorTurn a ratio like 3:16 into both fractions at once: the share of the whole, 3/19
• Ratio to Percentage CalculatorTurn any A to B ratio into a percentage. See the share of the whole and the A ov
• Relative Frequency CalculatorTurn counts into relative frequencies as decimals and percents, with cumulative
• Remainder CalculatorDivide two numbers and get the quotient, the remainder, the decimal answer and b
• Resultant Force CalculatorCombine two forces at an angle, or add a third, to get the resultant in newtons,
• Reynolds Number CalculatorGet the Reynolds number from density, velocity, length and viscosity, with unit
• Right Triangle CalculatorSolve a right triangle from any two sides, or one side and an angle. Get the thi
• Root CalculatorCalculate square roots, cube roots and nth roots with signed answers, exact form
• Rounding CalculatorRound numbers to decimal places or significant figures and compare half-up, ties
• SOHCAHTOA CalculatorUse SOHCAHTOA to solve a right triangle from two sides or one side and an angle.
• Scientific CalculatorFree online scientific calculator that reads a full expression: powers, roots, l
• Scientific Notation CalculatorConvert any number to scientific, engineering and E notation, see the coefficien
• Secant CalculatorGet sec(x) for any angle in degrees or radians, see the cosine it comes from, an
• Second Derivative CalculatorType a function and a point to get f'(x) and f''(x). See both derivative formula
• Sine CalculatorFind the sine of any angle in degrees or radians, with the cosecant included, pl
• Slope CalculatorFind the slope between two points with the angle, distance, line equation, perce
• Slope Intercept Form CalculatorTurn two points into slope intercept form: get m, b and the equation y = m x + b
• Slope Percentage CalculatorTurn rise and run into a percent grade, then read it as degrees, a 1:N ratio and
• Slugging Percentage CalculatorTurn at-bats, singles, doubles, triples and home runs into total bases and slugg
• Specific Heat CalculatorWork out the heat energy a material absorbs or releases from its mass, specific
• Spring Constant CalculatorFind a spring constant from a force and a stretch. Get k in N/m, N/cm and lbf/in
• Square Root CalculatorGet any square root as a decimal or a simplified radical. Perfect square checks,
• Square Root Curve CalculatorTurn a raw test score into its square root curve grade with 10 x sqrt(raw), see
• Standard Deviation CalculatorEnter a list of numbers to get the mean, variance and standard deviation, using
• Standard Error CalculatorFind the standard error of a mean, a share or a difference between means, with a
• Standard Form CalculatorConvert between Ax + By = C and y = mx + b, and read the slope, x intercept and
• Standard Form to Slope Intercept FormTurn Ax + By = C into y = mx + b with slope, intercept and every step shown. Han
• Statistics CalculatorPaste a data set to get the mean, median, mode, quartiles, IQR, sample and popul
• Sum of Squares CalculatorAdd up squared values or squared deviations for any list of numbers, with sample
• T Table (Student's t Distribution)Read a t table in two steps: pick the degrees of freedom row, then the tail colu
• Tangent CalculatorFind the tangent of any angle in degrees or radians, with cotangent and grade in
• Terminal Velocity CalculatorFind the terminal velocity of a falling object from its mass, area and drag coef
• Time to Decimal CalculatorTurn hours and minutes into decimal hours for payroll. Converts 7:45 to 7.75, ap
• Triangle CalculatorSolve any triangle from three sides, two sides and the included angle, or two an
• Trigonometry CalculatorGet sine, cosine, tangent, secant, cosecant and cotangent for any angle in degre
• Types of Chemical ReactionsLearn the five types of chemical reactions, balance four worked examples atom by
• Unit Circle CalculatorEnter any angle in degrees or radians to get sine, cosine, tangent, the quadrant
• Unit Vector CalculatorNormalize any 2D or 3D vector. Enter (3, 4) and get (0.6000, 0.8000), with the m
• Variance CalculatorEnter a data set and get the mean, sum of squares, sample variance, population v
• Vector Addition CalculatorAdd two or three vectors by magnitude and angle and get the resultant magnitude,
• Vector Magnitude CalculatorGet the length of a 2D or 3D vector from its x, y and z components, plus the uni
• Vector Projection CalculatorProject vector v onto u: get the scalar projection, the vector projection, the a
• Velocity CalculatorEnter two positions and two times to get average velocity in m/s, km/h, mph, ft/
• Water Velocity CalculatorWater velocity from flow and pipe size: GPM to fps and m/s, Schedule 40 inside d
• Wavelength CalculatorConvert frequency to wavelength and back for light and sound, with the speed for
• Weight Loss Percentage CalculatorEnter a start weight and a current weight to see the percent of body weight lost
• Weighted Average CalculatorEnter up to five values with their weights to get the weighted average, the plai
• Winning Percentage CalculatorWork out a win percentage from wins, losses and ties. 10-6-1 is .618 in the NFL
• Z Score CalculatorEnter a score, the mean and the standard deviation to get the z score, the perce
• ppm to mg/L ConverterConvert ppm to mg/L and back with the density correction that decides the answer

Most math you need in a normal week does not need a spreadsheet. You need a percentage, an average, a fraction reduced to its simplest form, or the area of something you are about to buy materials for. These calculators do that one job and show the formula behind the answer, so the number is not a black box.

The collection splits into a few groups. Percentages cover increases, decreases, error, change and the three questions people actually ask (what is X percent of Y, X is what percent of Y, and Y is X percent of what). Averages and statistics cover mean, median, mode, range, standard deviation, z-scores and confidence intervals, which is where most people first get lost. Number theory covers greatest common factors, least common multiples, factors, primes and fractions. Geometry covers area, perimeter, volume and the triangle and circle formulas. Physics covers force, velocity, energy and the gas laws, using the standard SI forms.

Each page states its formula in plain words before the calculator, works one example with real numbers, and lists the assumptions that make the result valid. If a formula has two common versions (for example, population versus sample standard deviation), the page names the one it uses and explains when the other applies.

Everything runs in the browser. Nothing you type is sent anywhere, and there is no sign-up. Use the search box if you already know the name of the formula, or browse the groups below.