- Fraction Calculator
- Matrix Calculator
- Slope Calculator
- Algebra Calculator
- Trigonometry Calculator
- Percentage Calculator
- Probability Calculator
-
Gacha Complete-Collection Expected Number of Draws CalculatorCalculate the expected number of gacha pulls or capsule-toy draws to collect every item in a set, using the Coupon Collector formula E(n)=n*H(n).
-
Hybrid Lognormal Distribution (PDF / CDF) CalculatorCompute the hybrid lognormal distribution HybLogN(rho x, mu, sigma): density f(x), lower cumulative P(x) and upper cumulative Q(x), tabulated over a range.
-
One-Sample Z-Test for SignificanceTest whether a sample mean differs significantly from a known population mean. Computes the z statistic, critical z, p-value, and reports significance.
-
Inverse Chi-Square Distribution Percent Point CalculatorFind the chi-square distribution quantile (percentage point) from a lower- or upper-tail probability and degrees of freedom by inverting the CDF. Free online tool.
-
Inverse Chi-Squared Distribution CalculatorCompute the PDF, lower and upper cumulative probability of the inverse chi-squared distribution for any point x and degrees of freedom nu.
-
Stirling Numbers of the Second Kind Table CalculatorCompute an exact table of Stirling numbers of the second kind S(n,k) for k = 0..n, with arbitrary-precision integers and the Bell number row sum.
-
Stirling Numbers of the First Kind (Table)Compute the full row of signed Stirling numbers of the first kind s(n,k) for k = 0..n. Enter n and get a clean table plus signed and absolute sums.
-
Stirling Numbers of the Second Kind S(n,k) CalculatorCompute the Stirling number of the second kind S(n,k): the number of ways to partition n labeled elements into k non-empty unlabeled subsets.
-
Stirling Number of the First Kind CalculatorCompute the signed Stirling number of the first kind s(n,k) for non-negative integers n and k, the falling-factorial coefficients, with a worked example.
-
Subset CalculatorCount the total number of subsets of an n-element set (2ⁿ) and the number of subsets of size k using the combination formula C(n,k).
-
Probability Someone Shares Your Birthday CalculatorFind the chance that at least one other person in a group shares YOUR exact birthday using p = 1 - (364/365)^(n-1). The "matches mine" birthday problem.
-
IQ Percentile CalculatorConvert any IQ score to its percentile rank using the normal distribution. Supports SD 15, 16 and 24 scales with the standard normal CDF.
-
Permutations with Repetition Table CalculatorBuild a table of permutations with repetition nΠr = n^r for a fixed set size n while r ranges from a start to an end value, with big-integer precision.
-
Incomplete Beta Function & Regularized Incomplete Beta Function Table CalculatorBuild a table of the lower incomplete beta function Bx(a,b) and the regularized incomplete beta Ix(a,b) over a range of x for given shape parameters a and b.
-
Combinations nCr Table CalculatorTabulate the binomial coefficients nCr for every r from 0 to n. Computes combinations with exact big-number arithmetic and the 2^n row sum, n up to 300.
-
Permutations nPr Table CalculatorGenerate a full table of permutations nPr for r = 0 to n using nPr = n!/(n-r)!. Exact big-integer results for ordered arrangements of distinct objects.
-
Combinations with Repetition Table CalculatorCompute a table of combinations with repetition H(n, r) = C(n+r-1, r) for n distinct items, with r ranging over any integer interval. Exact big-integer results.
-
Poisson Lambda from Cumulative Probability CalculatorSolve for the Poisson mean lambda from a known cumulative probability and percentile point x. Supports lower P(X less or equal x) and upper Q(X greater or equal x) modes.
-
Punnett Square CalculatorFree Punnett square calculator for a monohybrid cross. Enter both parents' alleles to get offspring genotype and phenotype ratios and probabilities.
-
Rock-Paper-Scissors Decisive Round Probability CalculatorCompute the probability a rock-paper-scissors (janken) game with n players is decided within r rounds, and rounds needed for a 99% chance of a decision.
-
Incomplete Beta Function CalculatorCompute the lower incomplete beta function B_x(a,b) by numerically integrating t^(a-1)(1-t)^(b-1) with Gauss-Legendre quadrature. Set x=1 for the complete beta function.
-
Combination with Replacement CalculatorCalculate combinations with replacement (multisets) using C(n+r-1, r). Enter the number of item types and items chosen to get the count instantly.
-
Permutation and Combination CalculatorFree permutation and combination calculator. Compute P(n,r) ordered arrangements and C(n,r) selections from n items instantly with formulas and examples.
-
Mean, Median, Mode, Range CalculatorCalculate the mean, median, mode, range, sum, min and max of any data set. Free online statistics calculator — just paste your numbers.
