Random Number Generator
The Random Number Generator produces numbers within a specified range. It can be useful for games, classroom activities, testing, simple simulations, selecting a random item, or other situations where a quick random value is needed.
How to use this calculator
- Enter the minimum value allowed by the range.
- Enter the maximum value allowed by the range.
- Generate a random number.
- Repeat the generation when you need another value from the same range.
Random number generation
For an integer range from minimum to maximum, a generated value is selected from the allowed values within that range.
- The generator uses the available random-number mechanism to select a value within the requested bounds.
- If the range is intended to include both endpoints, the minimum and maximum values can each be selected.
- Random generation for everyday selection is different from cryptographically secure randomness required for security-sensitive applications.
Worked examples
Example: choosing a number from 1 to 10
Set the minimum to 1 and the maximum to 10.
The generator can return any allowed integer in that range.
Example: a larger range
A range from 100 to 999 can be used when you need a random three-digit integer.
The generated value remains within the selected boundaries.
Understanding the result
Random generation does not mean that every short sequence will contain an even distribution of values. Random sequences can naturally contain repetitions or clusters.
The range determines which values are possible. Changing the range changes the set of possible results.
A general-purpose random-number generator should not automatically be assumed to provide cryptographic security.
Important notes
For passwords, authentication tokens, encryption keys, or other security-sensitive values, use a cryptographically secure random source designed for that purpose.
Repeated results are possible and do not necessarily indicate that a generator is malfunctioning.
For statistical experiments, consider the quality and properties of the random source required by your application.
Frequently asked questions
Can the minimum and maximum numbers be generated?
If the calculator uses an inclusive integer range, both endpoints are possible results.
Can the same random number appear twice?
Yes. Random generation can produce the same value more than once unless the system is specifically designed to prevent duplicates.
Is a random number generator suitable for passwords?
A general-purpose generator should not be assumed to be suitable for security-sensitive passwords or tokens. Those applications require a cryptographically secure random source.
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Related explanations
Learn the method behind the number or compare the terminology before using the calculator.
- How to Calculate Percent Error — Learn the percent error formula and how to compare an experimental value with a reference or accepted value.
This page provides a calculation tool plus explanatory information so you can understand what the result means and when the underlying method may not fit your situation.