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Geometric Distribution Calculator

Compute the probability of the first success on trial k (or after k failures) from the per-trial success probability p.

Related tools

All Statistics & probability tools →
Geometric mean calculatorCompute the geometric mean of a list of positive numbers.Beta Distribution CalculatorCompute beta-distribution probabilities on [0,1] from shape parameters α and β via the regularized incomplete beta function.Exponential Distribution CalculatorCompute exponential-distribution probabilities for waiting times from the rate λ, including P(X≤x), P(X>x) and a range.Gaussian Distribution GeneratorNormally-distributed numbers via Box–Muller, with an optional seed and the sample mean and SD.Hypergeometric Distribution CalculatorCompute hypergeometric probabilities of drawing k successes in n draws without replacement from a population of N with K successes.Negative Binomial Distribution CalculatorProbability of reaching the r-th success, counted either in failures before it or in total trials, with both parameterisations kept distinct.Normal Distribution CalculatorCompute normal probabilities P(X≤x), P(X>x), P(a≤X≤b) or find x for a percentile, from the mean and standard deviation.Weibull Distribution CalculatorCompute Weibull reliability probabilities F(x) and R(x) for failure analysis from the shape β and scale η.

Geometric Distribution Calculator works straight from this page — free, instant, nothing to install. It sits under Statistics & probability in our catalogue, alongside Geometric mean calculator and Beta Distribution Calculator.

How to use it

  1. Open the tool — no signup or install needed.
  2. Enter your input or adjust the available options.
  3. Get your result instantly, then copy or download it.

Frequently asked questions

What does Geometric Distribution Calculator do?

Compute the probability of the first success on trial k (or after k failures) from the per-trial success probability p.

When would I actually use this?

Summarising a dataset before drawing conclusions from it, checking whether a difference between two groups is real, and putting an interval around an estimate.

What is the most common mistake?

Reading a p-value as the probability that the hypothesis is wrong. It is the probability of seeing data at least this extreme if the null were true — a different statement, and a much weaker one.

How is Geometric Distribution Calculator different from Geometric mean calculator?

They sit next to each other but answer different questions: Geometric mean calculator is the one to open when you need it to compute the geometric mean of a list of positive numbers. Pick whichever matches what you're starting from — both are free.

Is there a tool for the next step?

Beta Distribution Calculator is the closest one after this: Compute beta-distribution probabilities on [0,1] from shape parameters α and β via the regularized incomplete beta function.

What else is worth having open alongside it?

Exponential Distribution Calculator and Gaussian Distribution Generator — they come up in the same task often enough to be worth a second tab.

Where do the figures come from?

Distributions and test statistics are computed from their standard definitions, not from a lookup table, so results carry more digits than a printed table would. The assumptions each test makes are stated with it.

Further reading

All guides →
ExplainerGeometric vs Arithmetic Mean: Which to UseThe arithmetic mean adds and divides; the geometric mean multiplies and takes a root. Learn which fits growth rates, ratios, and averages.ExplainerWhat Is a Percentile? The 90th Percentile ExplainedA percentile tells you where a value ranks within a group. Learn what the 90th percentile really means and why a percentile is not the same as a percentage.How-toHow to Calculate a Weighted AverageA weighted average gives some values more influence than others. Learn the Σ(w·x) / Σw formula with grade and portfolio examples you can follow step by step.How-toHow to Find a Cube Root by HandA step-by-step guide to finding a cube root by estimation and refinement — plus how it differs from a square root and when a value stays irrational.ExplainerHow Exponents Work: Powers and the Laws of ExponentsAn exponent is repeated multiplication. Learn the laws of exponents, what negative and fractional powers mean, and why anything to the zero is one.How-toHow to Calculate Percent Error: The Accuracy Formula for SciencePercent error tells you how close a measurement is to the true value. Learn the formula, work through an example, and see how scientists use it to judge accuracy.