Random Number Generator
Generate a random number within a specified range. Shows range width, expected value, and distribution properties of the uniform distribution.
Results
What is it?
A random number generator produces values from a uniform distribution — every outcome in the range is equally likely. This calculator shows the statistical properties of your specified range: the expected value (mean), standard deviation, and total number of possible outcomes.
How to use
Set minimum and maximum values and choose integer or decimal mode. The outputs describe the theoretical properties of the uniform distribution over your range. For generating an actual random number, click the refresh/randomise button in the UI (client-side feature) — the formula engine shows distribution statistics.
Example scenario
Rolling a standard six-sided die: min=1, max=6, integer mode. Range=5, expected value=3.5, SD≈1.708, 6 possible outcomes. Each face has a 1/6 ≈ 16.67% probability.
Pro tip
Pseudo-random number generators (PRNGs) used in computers are deterministic — they use a seed value. For cryptographic security, use a hardware RNG or a cryptographically secure PRNG (CSPRNG). When using random numbers for simulations (Monte Carlo methods), larger sample sizes produce more accurate estimates of real-world probabilities.