Calculate success and failure expected value inside each branch, weight each conditional branch value by its top-level probability, reconcile the branch probabilities to 100%,...

DRP

Defect Rate Probability Calculator

Use a binomial lot model for the defect-count threshold, then separate true defects into detected and missed paths using the entered inspection sensitivity.

CEV

Cards Expected Value Calculator

Combine card-event probability, trials, event and non-event payoffs, and entry cost to show expected count and value.

CDO

Card Draw Odds Calculator

Use combinations to count exact-target and zero-target hands under sampling without replacement, then convert them to hand probabilities and expected trial counts.

Lottery Odds Calculator

Count unordered main and bonus selections with combinations, multiply the independent outcome spaces, then use the complement rule for multiple distinct tickets.

DSO

Dice Sum Odds Calculator

Count exact sum combinations for identical fair dice, divide by the complete equally likely outcome space, and extend the probability to odds, expected hits, and entered...

DSOT

Dice Sum Outcome Table Calculator

Enumerate exact sum combinations for every displayed total from identical fair dice and divide each by the complete outcome space.

CTCD

Card Target Count Distribution Calculator

Generate the hypergeometric probability for every displayed target-card count using exact combinations without replacement.

CFO

Component Failure Odds Calculator

Estimate component failures and count variability from population, failure probability, observed failures, and a decision threshold.

DOCI

Dice Outcome Confidence Interval Calculator

Calculate a transparent normal-approximation interval for an observed dice outcome proportion, keep theoretical probability separate, and extend only the observed rate to a...

CDP

Card Draw Probability Calculator

Count unordered hands exactly, separating exact desired target-card count from the broader at-least-one probability and extending only the exact case to entered payoff arithmetic.

PEP

Poisson Event Probability Calculator

Set lambda equal to event rate times exposure, calculate the exact Poisson masses for zero, one, and two events, take the remaining mass as three or more, and keep expected...

SAO

System Availability Odds Calculator

Multiply independent essential component availabilities for the series chain, use the all-units-fail complement for the redundant subsystem, and multiply both blocks.

Dice Risk Calculator

Enumerate the exact sum distribution for the entered dice, count outcomes at or below the adverse threshold, convert that tail to a per-trial probability, and extend it to...

BEO

Binomial Event Odds Calculator

Use the binomial mass function for exactly k successes and sum the mass terms for cumulative tails, with expectation np and spread √np(1-p).

DEV

Dice Expected Value Calculator

Use the exact fair-dice sum distribution to calculate threshold probability, expected net value per play, horizon expectation, and the break-even win payout.

DEV

Discrete Expected Value Calculator

Multiply four outcomes by their entered probabilities, sum contributions, and derive variance from the second moment while displaying the probability total.

Lottery Probability Calculator

Count unordered ticket combinations with C(N, K), invert the count for one-line jackpot probability, combine independent lines with the complement rule, and compare...

PEO

Poisson Event Odds Calculator

Scale the Poisson rate by the number of equal intervals, evaluate e^-λ λ^k/k!

Dice Distribution Calculator

Enumerate the exact sum distribution for independent fair dice with identical side counts, then report exact-target and cumulative probabilities together with the theoretical...

Dice Simulation Calculator

Compare an exact fair-dice probability with the expected and entered observed result from a simulation run, including a sampling-error reference.

BEO

Binomial Exact Outcome Calculator

Evaluate the exact binomial mass at one success count using combinations and independent identical-trial probability, then show moments and repeated-group expectation.

CFP

Component Failure Probability Calculator

Multiply component count by mission periods to establish exposure, apply the independent per-period failure probability, use the complement rule for the chance of any failure,...

NEP

Normal Event Probability Calculator

Standardize each boundary with z=(x-μ)/σ, evaluate the standard normal CDF at both z-scores, and subtract the lower cumulative area from the upper.

Poisson Event Rate Calculator

Estimate an exposure-based event rate, scale it to 1,000 units, project future events, and display a transparent normal-approximation rate interval.

SAP

System Availability Probability Calculator

Calculate inherent availability from MTBF and MTTR, raise single-unit unavailability to the number of independent parallel units, then apply planned downtime over the stated...

DTP

Decision Tree Probability Calculator

Multiply along each path for joint probabilities, add mutually exclusive success leaves, apply Bayes’ rule for the posterior branch share, and probability-weight the outcome...

BEP

Binomial Event Probability Calculator

Use the binomial probability mass C(n,k)p^k(1-p)^(n-k), sum masses for cumulative probabilities, and keep the distribution mean and standard deviation beside the exact...

PLP

Portfolio Loss Probability Calculator

Model horizon return as normal, standardize the selected loss threshold, use the lower-tail CDF for breach probability, and use the inverse CDF for a one-sided parametric VaR...

Cards Simulation Calculator

Calculate and review cards simulation with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Cards Confidence Calculator

Calculate and review cards confidence with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Cards Risk Calculator

Calculate and review cards risk with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Cards Outcome Table Calculator

Calculate and review cards outcome table with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Lottery Distribution Calculator

Calculate and review lottery distribution with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Lottery Simulation Calculator

Calculate and review lottery simulation with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Lottery Expected Value Calculator

Calculate and review lottery expected value with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Lottery Confidence Calculator

Calculate and review lottery confidence with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Lottery Risk Calculator

Calculate and review lottery risk with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Lottery Outcome Table Calculator

Calculate and review lottery outcome table with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Component Failure Distribution Calculator

Calculate and review component failure distribution with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Component Failure Simulation Calculator

Calculate and review component failure simulation with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Component Failure Expected Value Calculator

Calculate and review component failure expected value with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Component Failure Confidence Calculator

Calculate and review component failure confidence with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Component Failure Risk Calculator

Calculate and review component failure risk with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Component Failure Outcome Table Calculator

Calculate and review component failure outcome table with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

System Availability Distribution Calculator

Calculate and review system availability distribution with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

System Availability Simulation Calculator

Calculate and review system availability simulation with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

System Availability Expected Value Calculator

Calculate and review system availability expected value with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

System Availability Confidence Calculator

Calculate and review system availability confidence with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

System Availability Risk Calculator

Calculate and review system availability risk with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

System Availability Outcome Table Calculator

Calculate and review system availability outcome table with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Binomial Event Distribution Calculator

Calculate and review binomial event distribution with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Binomial Event Simulation Calculator

Calculate and review binomial event simulation with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Binomial Event Expected Value Calculator

Calculate and review binomial event expected value with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Binomial Event Confidence Calculator

Calculate and review binomial event confidence with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Binomial Event Risk Calculator

Calculate and review binomial event risk with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Binomial Event Outcome Table Calculator

Calculate and review binomial event outcome table with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Poisson Event Distribution Calculator

Calculate and review poisson event distribution with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Poisson Event Simulation Calculator

Calculate and review poisson event simulation with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Poisson Event Expected Value Calculator

Calculate and review poisson event expected value with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Poisson Event Confidence Calculator

Calculate and review poisson event confidence with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Poisson Event Risk Calculator

Calculate and review poisson event risk with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Poisson Event Outcome Table Calculator

Calculate and review poisson event outcome table with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Normal Event Odds Calculator

Calculate and review normal event odds with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Normal Event Distribution Calculator

Calculate and review normal event distribution with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Normal Event Simulation Calculator

Calculate and review normal event simulation with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Normal Event Expected Value Calculator

Calculate and review normal event expected value with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Normal Event Confidence Calculator

Calculate and review normal event confidence with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Normal Event Risk Calculator

Calculate and review normal event risk with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Normal Event Outcome Table Calculator

Calculate and review normal event outcome table with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Decision Tree Odds Calculator

Calculate and review decision tree odds with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Decision Tree Distribution Calculator

Calculate and review decision tree distribution with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Decision Tree Simulation Calculator

Calculate and review decision tree simulation with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Decision Tree Confidence Calculator

Calculate and review decision tree confidence with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Decision Tree Risk Calculator

Calculate and review decision tree risk with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Decision Tree Outcome Table Calculator

Calculate and review decision tree outcome table with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Portfolio Loss Odds Calculator

Calculate and review portfolio loss odds with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Portfolio Loss Distribution Calculator

Calculate and review portfolio loss distribution with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Portfolio Loss Simulation Calculator

Calculate and review portfolio loss simulation with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Portfolio Loss Expected Value Calculator

Calculate and review portfolio loss expected value with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Portfolio Loss Confidence Calculator

Calculate and review portfolio loss confidence with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Portfolio Loss Risk Calculator

Calculate and review portfolio loss risk with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Match Outcome Probability Calculator

Calculate and review match outcome probability with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Match Outcome Odds Calculator

Calculate and review match outcome odds with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Match Outcome Distribution Calculator

Calculate and review match outcome distribution with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Match Outcome Simulation Calculator

Calculate and review match outcome simulation with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Match Outcome Expected Value Calculator

Calculate and review match outcome expected value with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Match Outcome Confidence Calculator

Calculate and review match outcome confidence with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Match Outcome Risk Calculator

Calculate and review match outcome risk with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Defect Rate Odds Calculator

Calculate and review defect rate odds with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Defect Rate Distribution Calculator

Calculate and review defect rate distribution with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Defect Rate Simulation Calculator

Calculate and review defect rate simulation with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Defect Rate Expected Value Calculator

Calculate and review defect rate expected value with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Defect Rate Confidence Calculator

Calculate and review defect rate confidence with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Defect Rate Risk Calculator

Calculate and review defect rate risk with the page's dedicated inputs, result breakdown, explanations, examples, and limitations.

Define the event before calculating its chance

Probability calculators describe uncertain events through probabilities, odds, expected values, combinations, permutations, and repeated-trial models. The sample space and event definition determine which formula is valid.

State whether trials are independent, whether selection uses replacement, and whether order matters. A calculated probability describes the chosen model; it does not guarantee a particular outcome in a small number of real trials.

Use combinations for unordered selections, permutations for arrangements, a binomial model for repeated independent trials, and expected value when outcomes must be weighted by their probabilities.

Directory guide

How to choose a probability calculator

Define the event precisely State what counts as success, whether outcomes are independent, and whether order or replacement matters.

Choose probability or odds Probability, decimal odds, fractional odds, expected value, and risk are related but not identical measures.

Check the model assumptions Combinations, permutations, binomial trials, cards, and dice require different sample spaces.

Calculator selection

Which probability calculator should I use?

Calculator	Main inputs	Main outputs	Best for
Probability Calculator	Event probability or favourable and total outcomes	Probability and complementary chance	Basic event probability
Combination Calculator	Population size and selection size	Unordered selection count	Selections where order does not matter
Permutation Calculator	Population size and arrangement size	Ordered arrangement count	Arrangements where order matters
Binomial Exact Outcome Calculator	Trials, success probability, and target successes	Exact-outcome probability	Independent repeated trials

Common tasks

If you try to calculate

Key terms

Probability calculation glossary

Sample space The complete set of outcomes included in a model.

Independent events Events for which one outcome does not change the other's probability.

Complement The event that the stated event does not occur.

Combination A selection in which order is ignored.

Permutation An arrangement in which order is distinguished.

Expected value The probability-weighted average of all modelled outcomes.

Probability

Choose a focus area

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