Directory
All Calculators
Every worksheet, grouped by job. Search the header if you already know a word of the name.
Descriptive Statistics
5 Number Summary CalculatorOrders the list and reports the minimum, lower quartile, median, upper quartile, and maximum with Hyndman-Fan type 7 quartiles.Arithmetic Mean CalculatorLeads with the ordinary mean and, when every value is positive, adds the geometric and harmonic means as comparisons.Average CalculatorAverages every typed value, or drops one high and one low first when the trim box is ticked and at least three values are present.Coefficient of Variation CalculatorDivides the sample standard deviation by the mean, and compares a second list when one is pasted.Descriptive Statistics CalculatorReports mean, median, mode, variance, standard deviation, range, and five-number summary together.Geometric Mean CalculatorAverages logarithms and exponentiates the result, and rejects any value that is zero or negative.Grouped Data Mean CalculatorEstimates a mean from class midpoints and frequencies, and rejects a class whose upper bound is below its lower bound.Harmonic Mean CalculatorDivides the count by the sum of the reciprocals, and rejects zero or negative values.Interquartile Range CalculatorSubtracts the lower quartile from the upper quartile and shows that gap as a share of the full range.Kurtosis CalculatorReports sample excess kurtosis, shifted so a normal-shaped sample lands near zero.Lower and Upper Fence CalculatorBuilds the 1.5 IQR fences and the 3 IQR extreme fences, then names every pasted point that falls outside.Mean Absolute Deviation CalculatorAverages the absolute distances from the arithmetic mean, and does not switch the center to the median.Mean CalculatorSplits a total into an equal share per observation and shows the sum and the count.Mean Median Mode CalculatorPuts the equal share, the middle rank, and the most repeated value on one ticket, and notes when they disagree.Median Absolute Deviation CalculatorTakes the median of the absolute distances from the median, then scales that result by 1.4826.Median CalculatorSorts the list and returns the middle value, averaging the two middle values when the count is even.Midrange CalculatorAverages the minimum and the maximum, and also averages the two quartiles as the midhinge.Mode CalculatorCounts repeats and reports every value that ties for the highest frequency.Pooled Standard Deviation CalculatorCombines two sample standard deviations into one spread and also reports the standard error of the difference of means.Pooled Variance CalculatorWeights two sample variances by their degrees of freedom and headlines the combined variance.Quartile CalculatorFinds Q1, Q2, and Q3 with Hyndman-Fan type 7 and reports the position each quartile came from.Range CalculatorSubtracts the minimum from the maximum and, when the extremes do not cancel, scales that gap by their sum.Root Mean Square CalculatorTakes the square root of the average square, and prints the arithmetic mean beside it as a comparison.Skewness CalculatorComputes adjusted Fisher-Pearson skewness from cubed standardized scores and names the skew band.Standard Deviation CalculatorReports the square root of the average squared distance from the mean, using n minus 1 unless the population box is ticked.Standard Error CalculatorComputes the standard error of a mean from a standard deviation and sample size.Standard Error of Proportion CalculatorReports the standard error of a sample proportion using p and n, or a hypothesized p0.Sum of Squares CalculatorAdds the squared distances from the mean and, beside that corrected total, adds the plain squares of the values.Variance CalculatorShows the sample variance and the population variance of one list side by side, and leads with the sample figure.Weighted Mean CalculatorAverages values that do not get equal votes, using the weight typed beside each value, and shows each weight's share.Z-Score CalculatorConverts a raw score into how many standard deviations it sits from the mean.Hypothesis Tests
ANOVA CalculatorOne-way ANOVA on two or more groups typed as separate lines of data.Chi-Square Critical Value CalculatorReturns the upper-tail chi-square cutoff for a given df and alpha.Chi-Square Goodness of Fit Test CalculatorCompares observed category counts with expected counts or expected proportions.Chi-Square Test CalculatorPearson chi-square test of independence for a contingency table of counts.Cochran's Formula CalculatorSizes a sample from a z cutoff and either a proportion or a known sigma, with an optional finite-population correction on the proportion path.Degrees of Freedom CalculatorReturns the degrees of freedom for one sample, two samples, Welch, paired data, ANOVA, chi-square, or a regression slope.F Critical Value CalculatorReturns the upper-tail F cutoff for numerator df, denominator df, and alpha.F-Test CalculatorCompares two sample variances with an F ratio and an upper-tail or two-sided p-value.Fisher's Exact Test CalculatorExact two-sided or one-sided p-value for a 2×2 table of counts via the hypergeometric distribution.One Proportion Z-Test CalculatorTests a sample proportion against a hypothesized p0 with a normal z statistic.One Sample T-Test CalculatorTests a mean against mu0 from a list of data, or from a sample mean, sample sd, and n.One Sample Z-Test CalculatorTests a sample mean against a hypothesized mean when the population sigma is known.P-Value CalculatorChooser that converts a z, t, chi-square, or F statistic into a p-value for the matching reference curve.P-Value from Chi-Square CalculatorConverts a chi-square statistic and degrees of freedom into an upper-tail p-value.P-Value from F CalculatorConverts an F statistic and its two degrees of freedom into an upper-tail p-value.P-Value from T CalculatorConverts a t statistic and degrees of freedom into a one-sided or two-sided p-value.P-Value from Z CalculatorConverts a standard normal z statistic into a one-sided or two-sided p-value.Paired T-Test CalculatorTests the mean of paired differences, from two matched columns or from a list of differences.R Critical Value CalculatorConverts a t cutoff on n minus 2 degrees of freedom into the critical Pearson correlation.Slovin's Formula CalculatorTurns a population and a proportional margin into a sample size, or inverts the same equation to recover the margin.T Critical Value CalculatorFinds the Student t cutoff for your degrees of freedom, alpha, and tail.T-Test CalculatorChooser for one-sample, two-sample pooled, or paired t tests from summary numbers.Two Proportion Z-Test CalculatorCompares two independent sample proportions with a pooled or unpooled z statistic.Two Sample T-Test CalculatorCompares two means with a pooled variance and df equal to n1 plus n2 minus 2.Two Sample Z-Test CalculatorCompares two means when both population standard deviations are known.Welch's T-Test CalculatorCompares two means without a pooled variance, using the Welch standard error and Satterthwaite df.Yamane's Formula CalculatorBuilds the half-and-half sample size, then lifts it for nonresponse and multiplies by a design effect.Z Critical Value CalculatorReturns the standard-normal cutoff for a chosen alpha and tail, and keeps the familiar table entries beside it as references.Z-Test CalculatorChooser for a one-mean z test, two-mean z test, or one-proportion z test when sigma or p0 is known.Probability
Bayes Theorem CalculatorTurns prevalence, sensitivity, and specificity into positive and negative predictive values and a count tree per 10,000 people.Binomial Distribution CalculatorGives the binomial point probability, both cumulative tails around k, and the mean and variance np(1 − p).Combination CalculatorComputes the exact integer nCr and, for a small n, shows the multiply-and-divide build.Conditional Probability CalculatorDivides a joint probability by P(B) and, when P(A) is present, checks whether independence approximately holds.Empirical Rule CalculatorApplies the 68-95-99.7 rule to a mean and standard deviation for a roughly normal set.Expected Value CalculatorSums value times probability, reports the variance, and warns when the probabilities miss 1 by more than 0.02.Exponential Distribution CalculatorUses the rate parameterization: density lambda e^(−lambda x), cdf 1 − e^(−lambda x), and mean 1/lambda.Factorial CalculatorReturns an exact integer factorial from 0 through 1000, or the gamma extension for a non-integer from 0 to 170.Geometric Distribution CalculatorUses the trials-until-first-success convention: P(X = k) = (1 − p)^(k − 1) × p, with mean 1/p.Hypergeometric Distribution CalculatorGives the probability of k successes in a draw without replacement, plus the mean nK/N.Inverse Normal Distribution CalculatorTurns a tail probability, a mean, and a standard deviation into the raw score that cuts off that tail.Modulo CalculatorShows the JavaScript truncated remainder, the floor remainder, and both quotients. Rejects a divisor of 0.Negative Binomial Distribution CalculatorCounts failures before the r-th success: C(k + r − 1, k) × p^r × (1 − p)^k, with mean r(1 − p)/p.Normal Approximation to Binomial CalculatorPlaces a continuity-corrected normal probability for P(X ≤ k) beside the exact binomial cdf when n is at most 200.Normal Distribution CalculatorTurns a raw score, a mean, and a standard deviation into a z-score, a density, and both tail probabilities.Percentile to Z-Score CalculatorConverts a percentile or cumulative probability into the matching standard normal z.Permutation CalculatorComputes the exact integer nPr = n! / (n − r)! as a falling product of r factors.Poisson Distribution CalculatorEvaluates the Poisson probability of a count and the cumulative probability, with mean and variance both equal to lambda.Probability CalculatorApplies one rule: the complement of p, the union of two events, or at least one success in n independent trials.Raw Score CalculatorRebuilds a raw score from a z-score, percentile, or tail probability plus a mean and sigma.Uniform Distribution CalculatorEvaluates a continuous uniform density and cdf on the interval from a to b, plus the mean and variance.Z-Score Probability CalculatorReturns the standard-normal probability to the left of z, to the right of z, or between two z values.Z-Score to Percentile CalculatorReports the left-tail percentile of a standard normal z-score.Confidence Intervals
Confidence Interval CalculatorBuilds a mean confidence interval from summary stats using a t critical value.Margin of Error CalculatorFinds a margin of error for a mean or proportion, or solves for the sample size that buys a target margin.Mean Confidence Interval CalculatorConfidence interval for a mean from raw data or from summary statistics.Mean Difference Confidence Interval CalculatorInterval for the difference of two independent means using pooled or Welch SE.Paired T-Test Confidence Interval CalculatorInterval for the mean of paired differences from raw pairs or summary stats.Proportion Confidence Interval CalculatorWilson score interval for a single proportion, with Wald shown underneath for comparison.Two Proportion Confidence Interval CalculatorInterval for the difference between two independent sample proportions.Regression and Correlation
Coefficient of Determination CalculatorTurns either a correlation or SSE and SST into r squared and the unexplained share.Correlation Coefficient CalculatorReports Pearson r and r squared from paired rows, with a verbal strength band.Covariance CalculatorComputes the sample covariance of two equal lists and prints both means.Exponential Regression CalculatorFits ln y = A + Bx for positive y, then rewrites the curve as y = a e to the Bx.Line of Best Fit CalculatorFits y = a + bx, reports residual SSE, and predicts y at a new x.Linear Regression CalculatorFits a line and tests the slope with a standard error, t, p-value, and 95 percent interval.Logistic Regression CalculatorFits an intercept and a slope to binary 0 or 1 outcomes and counts 0.5-cut matches.Multiple Linear Regression CalculatorFits y = b0 + b1 x1 + b2 x2 by least squares and reports R squared.Pearson R to P-Value CalculatorConverts a published Pearson r and sample size into a two-sided p-value.Pearson's Correlation Test CalculatorTests Pearson r with a two-sided t statistic and a decision at 0.05.Quadratic Regression CalculatorFits y = a + bx + cx squared and reports the equation and R squared.Spearman Correlation Coefficient CalculatorReplaces each column with average ranks and reports Pearson r on those ranks.Charts and Tables
Bar Chart MakerTallies categories or uses typed labels and values to produce bar heights and percents.Box Plot CalculatorBuilds a five-number summary with fences and lists mild and extreme outliers for a box plot.Frequency Table CalculatorBuilds a frequency and relative-frequency table from raw numbers or category labels.Histogram MakerBins numeric data into equal-width classes and reports frequencies for a histogram.Scatter Plot MakerSummarizes paired x,y points with correlation, means, and ranges for a scatter plot.Stem and Leaf Plot CalculatorSplits integers into stems and leaves and prints a stem-and-leaf display.Money and Pay
Break-Even CalculatorFinds units needed to cover fixed costs given price and variable cost per unit.CAGR CalculatorComputes compound annual growth rate between a start and end value over years.Compound Interest CalculatorGrows a principal with compound interest and optional monthly additions.Discount CalculatorApplies one or two stacked percent discounts without wrongly adding the percents.Hourly to Salary CalculatorAnnualises an hourly wage with optional overtime hours at a multiplier.Inflation CalculatorAdjusts a money amount forward or backward by an annual inflation rate.Loan Payment CalculatorAmortizes a fixed-rate loan with optional fees and extra monthly principal.Mortgage CalculatorComputes principal-and-interest payment plus tax, insurance, PMI, and HOA for a home loan.NHS Maternity Pay CalculatorIllustrates Agenda for Change occupational maternity pay plus editable statutory flat rate.Pro Rata Salary CalculatorProrates annual pay for starters and leavers by calendar days or working days.Refinance CalculatorCompares current loan payment with a refinance payment including closing costs.Reman CalculatorEstimates remanufactured-part cost from core charge, reman fee, and labour hours.Remap CalculatorEstimates wheel horsepower and torque from crank figures after a drivetrain loss percent.ROI CalculatorReturn on investment from gain and cost, reported as a ratio and a percent.Salary to Hourly CalculatorConverts an annual salary into an hourly rate from hours per week and paid weeks per year.Simple Interest CalculatorComputes simple interest I = Prt and optionally compares a compound figure on the same inputs.Teacher Pay CalculatorBuilds annual teacher pay from base scale, TLR, SEN, and inner/outer London allowances.Tip CalculatorSplits a bill with tip percent and optional tax, per person.VAT CalculatorAdds VAT to a net price or extracts VAT from a gross inclusive price.WASPI Compensation CalculatorIllustrates a weekly amount times years between two pension ages — not an official tariff.Health and Body
BAC CalculatorWidmark estimate of blood alcohol from drinks, weight, sex factor, and hours.Banfield Dosage CalculatorConverts a veterinarian's mg/kg instruction into a dose volume from concentration.BMI CalculatorBody mass index from metric or imperial height and weight.BMR CalculatorBasal metabolic rate from Mifflin-St Jeor and Harris-Benedict equations.Body Fat CalculatorU.S. Navy body-fat estimate from waist, neck, height, and (for women) hip.Calorie Deficit CalculatorEstimates daily intake from TDEE minus a chosen weekly loss pace using 7700 kcal per kg.Due Date CalculatorNaegele's rule: last menstrual period plus 280 days, with optional cycle-length adjustment.Ideal Weight CalculatorShows Devine, Robinson, and Miller ideal-weight formulas side by side.Insulin CalculatorMeal bolus from carbs÷ratio plus correction from (BG−target)÷factor, minus IOB.MAP CalculatorMean arterial pressure from systolic and diastolic blood pressure.Ovulation CalculatorEstimates ovulation and a fertile window from LMP and cycle length.PEth Test CalculatorMaps a PEth ng/mL result into common interpretive bands used in lab reports.Refill Date CalculatorProjects when a prescription runs out and suggests a refill date with a safety gap.TDEE CalculatorMultiplies BMR by an activity factor to estimate total daily energy expenditure.Water Intake CalculatorStarting-point daily water volume from body weight and an optional activity add-on.Math
Area of Circle CalculatorCircle area from radius or diameter using A = πr².Circumference CalculatorCircumference and area of a circle from radius or diameter.Exponent CalculatorEvaluates base^exponent for real bases and integer or real exponents where defined.Fraction CalculatorAdds, subtracts, multiplies, or divides two fractions and reduces the result.Logarithm CalculatorLog of a positive number in base 10, e, 2, or a custom base.Percentage Change CalculatorRelative percent change from an old value to a new value, plus the percentage-point gap.Pythagorean Theorem CalculatorSolves for a missing side of a right triangle from the other two sides.Scientific Notation CalculatorConverts between decimal form and a × 10^b scientific notation.Significant Figures CalculatorCounts significant figures in a number and rounds to a chosen sig-fig count.Slope CalculatorSlope of a line through two points, with rise, run, and intercept options.Square Root CalculatorPrincipal square root of a non-negative number, with optional n-th root.Volume CalculatorVolume of a box, cylinder, or sphere from the dimensions you enter.Home and Build
Concrete CalculatorConverts length, width, and depth into cubic yards and bag counts with waste.Decking CalculatorCounts deck boards, joists, and screws from area, board width, gap, and joist spacing.Flooring CalculatorConverts room dimensions into square footage and boxes of flooring with waste.Fuel Cost CalculatorTrip fuel cost from distance, economy, and price per litre or gallon.Gravel CalculatorConverts bed dimensions into cubic yards and tons using a density you can edit.Paint CalculatorEstimates paint cans from wall area after subtracting openings, coats, and coverage.Tile CalculatorCounts tiles for a floor or wall including grout gap and waste percent.School and Time
Age CalculatorAge in years, months, and days between a birth date and an as-of date.Date Difference CalculatorCounts whole days between two dates and shows an approximate years/months split.Final Grade CalculatorSolves for the final exam score needed to hit a course target given current mark and weights.GPA CalculatorWeighted GPA from grade points times credit hours.Percentage CalculatorFinds percentages, reverse percentages, and percentage change.Square Root Curve CalculatorApplies a square-root grading curve: curved = sqrt(raw/100)×100.Sports and Games
Blooket CalculatorIllustrative Blooket points from correct answers, streak, and editable multipliers.Destiny Matrix CalculatorReduces a birth date into destiny-matrix style numbers no larger than 22.Dynasty Trade CalculatorAdjusts fantasy values by age relative to a peak age for dynasty trades.Fantasy Trade CalculatorCompares two sides of a fantasy trade with editable position weights on projected points.IDP Trade CalculatorScores IDP fantasy trades with separate weights for DL, LB, and DB projections.Wordle CalculatorSummarises guess counts and computes average guesses from a typed distribution.This index is every calculator on Calculators King, grouped by the job rather than dumped into one alphabet. Use it when search is too narrow or when you want to see the neighbours before you commit to a formula. Each link lands on a page with one title, one worksheet, the steps, and five questions.
Skim the sentence under the name. It is the job, not a slogan. If the sentence mentions a divisor, a known sigma, a prescribed ratio, or a waste percent, that detail is the reason the page exists. Opening a near miss wastes the audit you were about to do.
Statistics come first because they are the largest shelf: description, tests, probability, intervals, regression, and charts. Money, health, math, home, school, and sports follow. A tool that sounds medical but is really a unit conversion, such as a prescribed pet dose turned into millilitres, stays with health and carries the veterinary warning on the page itself.
Urls match the titles. Hyphens separate words. Nothing is numbered, and nothing is called a template. If you remember only part of a name, the header search is faster than scrolling this directory on a phone. If you remember the family, the category row in the shelf on the home page jumps here with less hunting.
Blog essays sit beside the shelf when a choice needs more than a formula. They are dated 25-10-2026 and linked from the tool they discuss. They are not extra copies of the calculator text. Read them when you are deciding which page to open, then come back and run the numbers.
Questions people ask next
01How many calculators are on this index?
Every worksheet we publish is linked in the groups below. The count changes only when a genuinely different formula earns a page, not when a title is duplicated.
02Can I browse on a phone?
Yes. The groups stack in one column. Search in the header is still the fastest path if you know a word of the name.
03Do similar names mean similar tools?
They mean a shared family. Read the sentence under the name before you assume the inputs match. Pooled standard deviation is not the ordinary standard deviation page.
04Where are the blogs?
Under Blogs in the header. Each essay points at the calculator it discusses.
05What if a tool I need is missing?
Write to hello@calculatorsking.com with the job you need done. We add a page when the formula is distinct. We do not add a renamed copy of a page that already exists.