Probability Distributions

4.7
522 reviews
100K+
Everyone

Continuous probability distributions:
- Normal (Gaussian)
- t (Student's t)
- Chi-Squared
- F
- Exponential
- Gamma
- Beta
- Log-normal
- Weibull
- Uniform

Discrete probability distributions:
- Binomial
- Poisson
- Pascal (Negative Binomial)
- Geometric
- Hypergeometric
- Discrete Uniform

You can now calculate confidence intervals for "Both", "Middle", "Lower" and "Upper" tails. For example, if you want to find the 95% confidence interval of a Normal Distribution:
1. first select "Normal" distribution and select "Middle"
2. then enter "0.95" on the right side of the probability values
3. From and to values will be automatically calculated for you (-1.96, 1.96 in this case)

Help test the beta version of iOS app https://testflight.apple.com/join/eC4zBt6z

If you like the app, your review ❤️ and 5-⭐s are highly appreciated. Thank you!
Updated on
Nov 6, 2023

Data safety

Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
No data shared with third parties
No data collected

Ratings and reviews

4.7
497 reviews
letsb3nameless
October 4, 2022
Useful since I dont have a graphics calculator, however it isn't super user friendly (no text wrapping for answers, answer goes offscreen for "both tails" mode). I'm just glad there arent that many invNorm or normalCDF questions to study. Overall pretty useful anyway, made my life easier.
3 people found this review helpful
October 5, 2022
Updated: Hi, thanks for the review. Please update to the latest version of the app where this should be fixed.
January 15, 2020
OMG! FINALLY! A probability calculator that actually works. Thank you. There are a lot out there that claim to calculate probability and z scores but they dont. This one actually works, though I don't think it figures out z scores, but I know how to do that on my own.
20 people found this review helpful