Random Number Generator

Generate random integers or decimals within your specified range

Formula

Integer: Math.floor(Math.random() × (max - min + 1)) + min; Decimal: Math.random() × (max - min) + min

Uses JavaScript's Math.random() (pseudo-random). For unique numbers, uses Fisher-Yates shuffle on the available pool.

How to Calculate Manually

1
Select integer or decimal
2
Set minimum and maximum values
3
Choose how many numbers to generate
4
Decide if duplicates are allowed
5
For decimals: set decimal places
6
Click generate - numbers appear instantly

Reference Table

Use Case	Settings	Example
Dice Roll	Integer 1-6, count 1	4
Lottery Numbers	Integer 1-49, count 6, no dupes	7, 23, 31, 42, 45, 48
Random Sample	Integer 1-1000, count 50	Various
Monte Carlo	Decimal 0-1, count 10000	0.234, 0.876, ...
Random Password	Integer 33-126, count 16	ASCII chars

Random Number Generator: Uses, Methods, and Best Practices

Random numbers are essential for simulations, cryptography, gaming, statistical sampling, and many other applications. Understanding how random number generation works helps you choose the right tool for your needs...

Frequently Asked Questions

Is this cryptographically secure? No, this uses Math.random() which is pseudo-random. For cryptographic use, use Web Crypto API (crypto.getRandomValues).: No, this uses Math.random() which is pseudo-random. For cryptographic use, use Web Crypto API (crypto.getRandomValues).
Can I generate non-repeating numbers? Yes, disable 'Allow Duplicates' to get unique numbers within the range. Range must be large enough for the count requested.: Yes, disable 'Allow Duplicates' to get unique numbers within the range. Range must be large enough for the count requested.
What's the maximum range? JavaScript's safe integer range is -(2^53-1) to 2^53-1. This calculator supports the full safe integer range.: JavaScript's safe integer range is -(2^53-1) to 2^53-1. This calculator supports the full safe integer range.

Calculator

Formula

Formula

How to Calculate Manually

Reference Table

Random Number Generator: Uses, Methods, and Best Practices

Frequently Asked Questions

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