Random Number Generator

Math

Generate true pseudorandom numbers, integers, or decimals within any custom range with presets for dice rolls, lotteries, and PINs.

Quick Presets:

5 Numbers Generated

4 10 52 93 40

Min 4

Max 93

Sum 199

Average 39.8

How This Calculator Works

A random number generator produces an unpredictable sequence of numbers drawn uniformly from a specified range [min, max]. Our generator utilizes modern hardware-backed cryptographic random generation (CSPRNG via Web Cryptography API), ensuring genuine statistical uniformity without predictable seed patterns.

📐 Discrete Uniform Probability Distribution

P(X = k) = 1 / (Max - Min + 1) | k ∈ [Min, Max]

Min: Lower bound integer of the desired interval

Max: Upper bound integer of the desired interval

Count: Total quantity of random numbers to generate

P(X = k): Equal probability of selecting any specific number k

Key Mathematical Rules & Properties

Uniform Distribution

Every valid integer between Min and Max has exactly identical mathematical likelihood of being selected.

Unique Sampling (No Duplicates)

When unique numbers are chosen, the generator uses the Fisher-Yates algorithm to ensure unbiased sampling without replacement.

Floating-Point Decimals

When decimal places are enabled, continuous uniform floating-point values are generated and rounded to the chosen precision.

Hardware Entropy Security

Uses crypto.getRandomValues() to sample entropy from CPU thermal noise and operating system CSPRNG pools.

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Worked Example: Simulating a 6-Sided Die Roll

Roll three fair six-sided dice and sort the outcomes ascending.

Set Min = 1, Max = 6, Count = 3, Allow Duplicates = Checked.
Each die roll has an independent 1/6 (16.67%) probability.
Randomly sample 3 values: e.g. [4, 1, 6].
Sort ascending: [1, 4, 6].

Final Answer: 1, 4, 6

Frequently Asked Questions

Are these random numbers pseudo-random or true random?

They are generated using the browser cryptographically secure pseudorandom number generator (CSPRNG), which draws entropy from system hardware events, making them virtually indistinguishable from true random noise.

How do I generate official lottery numbers?

Uncheck "Allow Duplicates", set Count to your lottery ticket size (e.g., 6 numbers), set Min = 1 and Max = 49 (or 69), and choose Ascending sort.

What is the maximum quantity of numbers I can generate at once?

Up to 1,000 numbers in a single generation, with instant copy-to-clipboard and formatted delimiters (comma, space, or line breaks).

What happens if Count is larger than the range without duplicates?

If duplicates are disabled, Count cannot exceed (Max - Min + 1). For example, you cannot choose 15 unique numbers between 1 and 10.

Understanding your calculation

Method, example and limitations

How the calculation works

The generator selects values within the specified bounds according to its chosen integer or decimal mode. Repeated draws can produce the same value unless uniqueness is explicitly requested.

Example to check

For integers from 1 through 6, every valid result must belong to {1, 2, 3, 4, 5, 6}; a repeat of 4 on two draws can be legitimate.

Before using the result

A short sequence need not look evenly distributed. Do not treat a general-purpose random-number tool as a cryptographically secure generator or a regulated prize-draw system.

Calculation methodology · Report a result that needs review