Random Number Generator
Generate random whole numbers in a range, with or without duplicates.
What the Random Number Generator does
Generates uniformly distributed whole numbers between your bounds, inclusive of both ends. Choose unique draws for raffles and team picking, or allow repeats to simulate dice and coin flips.
Formula
value = min + ⌊random() × (max − min + 1)⌋
Inputs explained
| Input | Unit | Required | Notes |
|---|---|---|---|
| Minimum | number | Yes | — |
| Maximum | number | Yes | — |
| How many numbers | number | Yes | Accepts 1 or more, up to 1000. |
| Allow repeats? | one of 2 options | Yes | — |
How to use it
- Choose Allow repeats?.
- Enter Minimum, Maximum and How many numbers.
- Select Calculate.
Worked example
Pick 6 lottery numbers from 1 to 49 with no repeats.
- Minimum
- 1
- Maximum
- 49
- How many
- 6
- Repeats
- No repeats
Six distinct numbers such as 4, 11, 23, 30, 38, 45.
Reading the result
- Both bounds are included, so a range of 1 to 6 can return either 1 or 6.
- Unique draws suit raffles and team selection; allowing repeats models dice and coin flips, where every roll is independent.
Assumptions and limitations
- Numbers come from the browser’s pseudo-random generator. That is fine for games, sampling and picking a winner, but it is not suitable for cryptographic keys or anything where predictability would matter.
Common mistakes
- Expecting an even spread in a small sample. Genuine randomness clusters, and runs of repeats are normal.
- Requesting more unique numbers than the range contains, which cannot be satisfied.
Frequently asked questions
Is this truly random?
It is pseudorandom — statistically uniform and fine for games, picking and sampling, but not for keys, passwords or anything security-related.
Are the endpoints included?
Yes. Both the minimum and maximum can be drawn.