Quick answer
Each value is min + ⌊u × (max − min + 1)⌋ where u is a pseudo-random number in [0, 1). With minimum 1, maximum 100 and seed 42 the calculator returns 61, 45, 86, 67, 18, which sum to 277, and the same seed gives the same list every time.
Enter the range, how many numbers you want, and optionally a seed. The calculator returns the numbers and their sum. It is a random number generator with an optional seed.
Related tools: Prime Number Calculator: Check whether a number is prime and find the next prime. Complex Number Calculator: Add, subtract, multiply and divide complex numbers. Scientific Calculator: Evaluate expressions with functions, constants, powers and factorials.
How to use the Random Number Generator
- Enter minimum (a whole number). It starts at 1.
- Enter maximum (a whole number). It starts at 100.
- Enter how many (a whole number, between 1 and 1000). It starts at 5.
- Optionally, enter seed (optional, for repeatable results) (a whole number).
- Press Calculate to see the result, and use Reset to start again.
| Input | What to enter | Allowed values |
|---|---|---|
| Minimum | A whole number | starts at 1 |
| Maximum | A whole number | starts at 100 |
| How many | A whole number | ≥ 1, ≤ 1000, starts at 5 |
| Seed (optional, for repeatable results) (optional) | A whole number | — |
Formula and method
Formula
value = min + ⌊u × (max − min + 1)⌋, u ∈ [0, 1)
IEEE-754 double precision; shown to at most 6 decimal places.
With a seed the numbers come from the mulberry32 generator, so the same seed always gives the same list. Without a seed the browser's cryptographic generator is used. Not suitable for security-critical secrets.
Worked examples
These examples are verified: each one is an automated test case that the live calculator must reproduce exactly.
Example 1
Inputs: Minimum = 1; Maximum = 100; How many = 5; Seed (optional, for repeatable results) = 42.
| Result | Value |
|---|---|
| Random numbers | 61, 45, 86, 67, 18 |
| Sum | 277 |
Example 2
Inputs: Minimum = 1; Maximum = 6; How many = 4; Seed (optional, for repeatable results) = 7.
| Result | Value |
|---|---|
| Random numbers | 1, 1, 6, 5 |
| Sum | 13 |
The first line is the headline result (random numbers). Below it the random Number Generator lists sum, which describe the same case from other angles. IEEE-754 double precision; shown to at most 6 decimal places.
Seeds and repeatability
A seed makes the sequence repeatable, useful for demonstrations and sampling you want to reproduce. Leave it blank for a different list each time.
Not for security
The numbers come from a pseudo-random generator, fine for games, sampling and raffles you run yourself, but not for passwords, keys or anything where an attacker could benefit from predicting the values. Duplicates can appear, because each draw is independent. The tool returns at most 1,000 values.
How the result changes with minimum
Holding every other input at the first worked example, this table changes only minimum. It shows how sensitive the answer is to that one value; each row was produced by running this calculator.
| Minimum | Random numbers | Sum |
|---|---|---|
| 1 | 61, 45, 86, 67, 18 | 277 |
| 2 | 61, 46, 86, 68, 19 | 280 |
| 4 | 62, 47, 86, 68, 20 | 283 |
What happens with invalid input
These messages are produced by the calculator itself, so you know what to fix.
- Maximum: entering "1" shows "Maximum must be at least the minimum." beside that field and no result.
- How many: entering "0" shows "How many must be at least 1." beside that field and no result.
Choosing between the Random Number Generator and similar calculators
Each row shows what a related calculator on this site asks for and what it returns, so you can pick the one that matches your question.
| Calculator | You enter | It returns |
|---|---|---|
| [Prime Number Calculator](/math/prime-number-calculator/) | number | Result |
| [Complex Number Calculator](/math/complex-number-calculator/) | real part of z₁, imaginary part of z₁ and operation | Result |
| [Scientific Calculator](/math/scientific-calculator/) | expression and angle mode | Result |
| [Roman Numeral Converter](/math/roman-numeral-converter/) | convert and value | Roman numeral |
| [Fibonacci Sequence Calculator](/math/fibonacci-sequence-calculator/) | position n | F(10) |
Assumptions and limitations
- Maximum must be at least the minimum
- At most 1,000 values
If a required value is empty, not a number, or outside its allowed range, the form marks that field with a message and shows no result instead of a misleading number. The automated checks deliberately try invalid entries for maximum and how many to confirm this.
Frequently asked questions
Can numbers repeat?
Yes, each draw is independent.
Is it truly random?
It is pseudo-random.
Can I use it to pick a winner?
Yes, with a published seed for transparency.
What does the Random Number Generator calculate?
Random integers in a range, optionally repeatable with a seed. It returns Random numbers and Sum.
What formula does the Random Number Generator use?
value = min + ⌊u × (max − min + 1)⌋, u ∈ [0, 1). With a seed the numbers come from the mulberry32 generator, so the same seed always gives the same list.
What do I need to enter in the random Number Generator?
You enter Minimum, Maximum and How many. Optional: Seed (optional, for repeatable results).
How is the result rounded or limited?
IEEE-754 double precision; shown to at most 6 decimal places. Maximum must be at least the minimum.
What are the limits of this calculator?
Maximum must be at least the minimum. At most 1,000 values.
What is an example of a random Number Generator result?
With minimum 1, maximum 100, how many 5 and seed (optional, for repeatable results) 42, the random numbers is 61, 45, 86, 67, 18.
Where does the method come from?
The method follows: mulberry32 PRNG (Tommy Ettinger, public domain).
Related calculators
- Prime Number Calculator — Check whether a number is prime and find the next prime.
- Complex Number Calculator — Add, subtract, multiply and divide complex numbers.
- Scientific Calculator — Evaluate expressions with functions, constants, powers and factorials.
- Roman Numeral Converter — Convert between numbers and Roman numerals (1–3999).
- Fibonacci Sequence Calculator — The nth Fibonacci number and the sequence leading to it.
- Factorial Calculator — n! computed exactly.
Sources
- mulberry32 PRNG (Tommy Ettinger, public domain)
Content last reviewed 2026-11-04. Formulas and worked examples are checked by automated tests against independently computed values.