Random Number Generator Calculator
Draw whole numbers from any range, with or without repeats, from an explicit seed — so the same seed always reproduces the same draw and anyone can check it.
Random Number Generator Calculator: with the default inputs, your numbers (draw order) is 60, 63, 89, 71, 91.
Inclusive — the maximum can itself be drawn.
On: every number is different, like a raffle. Off: each draw is independent, like rolling a die.
Change this for a different draw. The same seed always gives the same numbers — that is what makes the result checkable.
- Sorted
- 60, 63, 71, 89, 91
- Sum
- 374
- Average
- 74.8
- Smallest drawn
- 60
- Largest drawn
- 91
Assumptions
- The draw is a pure function of the inputs — the same seed always produces the same numbers.
- mulberry32 is a non-cryptographic PRNG: fine for raffles and sampling, unsuitable for security.
- Both ends of the range are inclusive, and only whole numbers are drawn.
| Draw | Number | Running total |
|---|---|---|
| 1 | 60 | 60 |
| 2 | 63 | 123 |
| 3 | 89 | 212 |
| 4 | 71 | 283 |
| 5 | 91 | 374 |
How this is worked out
The formula
Each draw takes a uniform value u in [0, 1) and maps it to ⌊lo + u × (hi − lo + 1)⌋, so every integer from lo to hi inclusive is equally likely. Without repeats, a partial Fisher-Yates shuffle picks n distinct values in n steps. The uniform stream comes from mulberry32 seeded with the seed you supply, so the whole result is a deterministic function of (min, max, count, repeats, seed).
Open How it’s calculated above to see this worked through with your own numbers.
What you enter
- Minimum
- A number.from -1000000000 to 1000000000 · whole numbers only · defaults to 1
- Maximum
- Inclusive — the maximum can itself be drawn.from -1000000000 to 1000000000 · whole numbers only · defaults to 100
- How many numbers
- A number.from 1 to 100 · whole numbers only · defaults to 5
- No repeats
- On: every number is different, like a raffle. Off: each draw is independent, like rolling a die.defaults to on
- Seed
- Change this for a different draw. The same seed always gives the same numbers — that is what makes the result checkable.from 0 to 1000000000 · whole numbers only · defaults to 12345
What you get back
- Your numbers (draw order)main answer
- Sorted
- Sum
- Average
- Smallest drawn
- Largest drawn
What this assumes
- The draw is a pure function of the inputs — the same seed always produces the same numbers.
- mulberry32 is a non-cryptographic PRNG: fine for raffles and sampling, unsuitable for security.
- Both ends of the range are inclusive, and only whole numbers are drawn.
About this calculator
This generator draws whole numbers from a range you choose — for raffles, sampling, test data, team picking, or anything else that needs an impartial choice.
Why there is a seed
Every other calculator on this site returns the same answer every time you run it, and this one does too. That is deliberate. The results are recomputed whenever the page is loaded, shared or checked, so a generator using the browser's built-in randomness would show different numbers to different people looking at the same link — and there would be no way to verify what was drawn.
Instead, the numbers come from a seeded pseudo-random generator (mulberry32). The seed is just another input: change it and you get a completely different draw; keep it and you get the same draw forever, on any device. That makes a result reproducible and auditable — you can publish the seed before a draw and let anyone reproduce it afterwards.
To get fresh numbers, change the seed. Any number works; people often use the date, or a number called out loud in front of witnesses.
Repeats or no repeats
- No repeats (the default) is a draw without replacement, like pulling raffle tickets from a hat. Every number is different. It uses a partial Fisher-Yates shuffle, which is unbiased and finishes in exactly as many steps as you asked for.
- Repeats allowed is a draw with replacement, like rolling a die over and over. Each draw is independent, so duplicates are normal — and much more common than intuition suggests. Draw 23 numbers from 1–365 and there is a better-than-even chance two match. That is the birthday problem, and it is not a bug.
Where to be careful
Do not use this for anything security-sensitive. Passwords, tokens, keys, shuffles in a real-money game — none of those should come from a seeded 32-bit generator, because anyone who learns the seed can reproduce every number. Use a cryptographically secure source instead: your operating system's random device, or the crypto API in your language.
For fairness in a raffle or a lottery-style draw, the mathematics here is sound and every value in range is equally likely; the honesty comes from committing to the seed publicly before the draw rather than from the generator itself.
Finally, the range is inclusive at both ends — a minimum of 1 and a maximum of 100 can produce both 1 and 100.
Frequently asked questions
▸Why do I get the same numbers every time?
Because the draw is seeded, so the result can be reproduced and checked. Change the seed and you get an entirely different set of numbers.
▸How do I get a new set of numbers?
Change the seed to any other whole number. People often use today's date, or a number chosen in front of witnesses so the draw can be verified afterwards.
▸Is this random enough for a raffle?
Yes for fairness — every number in range is equally likely and the draw is unbiased. Publish the seed before the draw so participants can verify the result themselves.
▸Can I use this to generate a password?
No. A seeded 32-bit generator is predictable to anyone who knows the seed. Use your operating system's cryptographic random source for anything security-related.
▸Are the minimum and maximum included?
Yes, both ends are inclusive. A range of 1 to 100 contains exactly 100 possible values, and both 1 and 100 can be drawn.
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