About the Random Number Generator
A random number generator produces an unpredictable integer within a range you set. It is what you reach for to pick a winner, assign participants to groups, choose a sample, settle a decision, or simulate a die roll — any situation where the point is that nobody controls the outcome.
The formula
n = floor( random() · (max − min + 1) ) + minrandom() returns a value between 0 and 1. Scaling it to the size of the range, taking the floor, and adding the minimum yields a uniformly distributed integer from min to max inclusive.
How to use this calculator
- 1Enter your Minimum Value. The field starts at
1, which you can overwrite. - 2Enter your Maximum Value. The field starts at
100, which you can overwrite. - 3Read the result straight away — it recalculates as you type, so there is no button to press. Use Share to copy a link that reopens the page with your exact numbers filled in.
Worked example
| Input | Value |
|---|---|
| Minimum Value | 1 |
| Maximum Value | 100 |
Result
Random Number:
65
Those are the values the page loads with, so you can reproduce this result yourself and then change one field at a time to see what drives the outcome.
Understanding your result
This generator is pseudorandom: an algorithm produces a sequence that passes statistical tests for randomness but is ultimately determined by an internal seed. For games, sampling, and everyday choices this is indistinguishable from true randomness. For cryptography it is not, because a predictable seed makes the output predictable.
Uniform means every integer in the range is equally likely, but that does not mean results will look evenly spread. Genuine randomness clusters — repeats and short runs are expected, and their absence is what would be suspicious. In twenty rolls of a six-sided die, seeing the same number three times in a row is unremarkable.
Things worth knowing
- The range is inclusive at both ends, so 1 to 100 can return 1 and 100.
- Each draw is independent. A previous result never changes the odds of the next one.
- For drawing without repeats — a raffle where nobody wins twice — remove each result before drawing again.
- For security purposes such as passwords or tokens, use a cryptographically secure generator instead.
- The gambler's fallacy is the belief that a number is "due". It is not; the generator has no memory.
Frequently asked questions
Are these numbers truly random?+
They are pseudorandom — generated by an algorithm that passes statistical randomness tests but is deterministic given its seed. This is fine for games, sampling, and decisions, but not for cryptographic use.
Can the same number appear twice?+
Yes. Each draw is independent, so repeats are expected rather than a fault. If you need unique results, remove each number from the range after it is drawn.
Are the minimum and maximum included?+
Both are. A range of 1 to 6 can produce 1, 2, 3, 4, 5, or 6, each with equal probability.
Is this fair enough for a giveaway?+
For most purposes yes, since every number in the range is equally likely. For anything with legal or financial consequence, use a documented, auditable drawing process.