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Calcrivo

Random Number Generator

Generate a random whole number between any two values.

Inputs

Increment this to generate a fresh random number.

Random Number

91

Range Low

1

Range High

100

Step by step

  1. Determine the range

    [1, 100]

    = 100 possible integers

  2. Draw a uniform pseudo-random float from [0, 1)

    Uses the browser's built-in Math.random() — cryptographically unpredictable for all practical purposes.

  3. Scale, floor, and shift into the target range

    floor( random() × 100 ) + 1

    Each integer in the range is equally likely.

  4. Result

    = 91

How it works

This picks a uniformly random whole number between your minimum and maximum, inclusive of both ends. Change the minimum, maximum, or the re-roll field to draw a new number.

Formula

Uniform integer in [min, max]

r = floor( random() × (max − min + 1) ) + min

random()
Pseudo-random float uniformly drawn from [0, 1)
min
Inclusive lower bound
max
Inclusive upper bound
r
The resulting random integer

Frequently Asked Questions

Is this truly random?

It uses your browser's built-in pseudo-random generator, which is statistically random and perfect for games, giveaways, and everyday picks — but not for cryptographic security.

How do I get a new number?

Adjust any input, including the dedicated re-roll field, and a fresh random number is generated instantly.

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