Probability Calculator Plus
Stats, Distributions & Venn
$2.99 · Designed for iPad. Not verified for macOS.
Master probability and statistics with Probability Calculator — the most complete probability calculator for students, teachers, and data enthusiasts.
Whether you're studying for an exam, teaching a class, or working through real-world statistics problems, ProbCalc gives you instant answers with full step-by-step solutions so you truly understand the math.
- PROBABILITY CALCULATIONS -
• Basic Probability — Calculate P(A) from favorable and total outcomes
• Conditional Probability — Solve P(A|B) = P(A∩B) / P(B)
• Independent Events — Multiply probabilities across multiple events
• Dependent Events — P(A∩B) = P(A) × P(B|A)
• Venn Diagram Calculator — Input P(A) and P(B), instantly get P(A∩B), P(A∪B), P(A XOR B), and occurrence probabilities over N trials — complete with visual Venn diagram
• Custom Calculator — Enter values as fractions, decimals, or percentages
- STATISTICAL DISTRIBUTIONS -
• Binomial Distribution — P(X=k), mean, variance, and standard deviation
• Normal Distribution — P(a ≤ X ≤ b) with z-score computation and CDF
• Poisson Distribution — P(X=k) with λ parameter, mean, and variance
-RANDOM EXPERIMENT SIMULATOR -
Roll dice, flip coins, and draw cards — all with real probability charts:
• Dice: D4, D6, D8, D10, D12, D20 (roll up to 6 at once)
• Coins: Flip 1–10 coins simultaneously
• Cards: Draw from a standard 52-card deck
• Live frequency chart updates with every trial
- STEP-BY-STEP SOLUTIONS -
Every calculation shows the full working — formula, substitution, and result. Perfect for checking homework, preparing for exams, or learning how probability really works.
- CALCULATION HISTORY -
Every result is automatically saved. Search, review, and copy any previous calculation. Swipe to delete. Tap for full detail with all steps.
-REFERENCE GUIDE -
Built-in reference includes:
• Complete probability and distribution formulas
• Standard Normal Z-table (z = −3.0 to +3.0)
• Interactive combinations C(n,r) and permutations P(n,r) calculator
- DESIGNED FOR EVERYONE -
Clean, distraction-free interface with full Dark Mode support. Tap any result to copy it instantly. Works on iPhone and iPad.
No ads. No subscriptions. No internet required.
Perfect for:
• High school and university statistics courses
• AP Statistics, IB Math, A-Level, SAT/ACT prep
• College probability and statistics classes
• Teachers preparing lessons and examples
• Data analysts and business professionals
Probability is the measure of the likelihood that an event will occur. Probability is quantified as a number between 0 and 1, where, loosely speaking, 0 indicates impossibility and 1 indicates certainty.
Summary of probabilities:
Probability that both the events occur P(A ∩ B) = P(A) x P(B).
Probability that either of event occurs P(A U B) = P(A) + P(B) - P(A ∩ B).
Conditional Probability P(A | B) = P(A ∩ B) / P(B).
Conditional Probability P(B | A) = P(A ∩ B) / P(A).
Exclusive OR of A and B P(A XOR B) = P(A) + P(B) - 2 X P(A ∩ B).
Probability theory is used widely in such areas of study as mathematics, statistics, finance, gambling, science (in particular physics), artificial intelligence/machine learning, computer science, game theory, and philosophy to, for example, draw inferences about the expected frequency of events.
Probability theory is applied in everyday life in risk assessment and modeling. The insurance industry and markets use actuarial science to determine pricing and make trading decisions. Governments apply probabilistic methods in environmental regulation, entitlement analysis (Reliability theory of aging and longevity), and financial regulation.
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Ratings & Reviews
- Optimized for the latest devices.
- Fixed minor bugs.
- Improved and redesigned the UI.
The developer, Heng Jia Liang, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Heng Jia Liang
- Size
- 1.2 MB
- Category
- Education
- Compatibility
Requires iOS 17.6 or later.
- iPhone
Requires iOS 17.6 or later. - iPad
Requires iPadOS 17.6 or later. - Mac
Requires macOS 14.6 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.3 or later.
- iPhone
- Languages
English and 8 more
- English, French, German, Japanese, Korean, Portuguese, Simplified Chinese, Spanish, Traditional Chinese
- Age Rating
4+
- 4+
- Copyright
- © Heng Jia Liang
