Random Number Generator
Generate one or more random whole numbers between any minimum and maximum you choose. This free online developer calculator runs entirely in your browser — no signup, no data sent anywhere.
Inputs
Results
How It Works (Formula & Method)
For a range from min to max inclusive, each number is computed as floor(random() × (max − min + 1)) + min, where random() returns a value in [0, 1). This maps the continuous random value evenly onto the integer range. If you request several numbers they are generated independently, so repeats can occur.
Worked Example
Below is a worked example using the calculator's default values. The same numbers are pre-filled in the form above so you can press Calculate and see the result without typing anything.
Inputs used:
- Minimum: 1
- Maximum: 100
- How Many (1–100): 5
With these inputs, the calculator computes the metrics shown in the Results panel. Change any value and press Calculate again to see how the result responds — the live widget and the chart both update instantly.
About the Random Number Generator
Random numbers drive simulations, test data, sampling, raffles, and games. This generator produces uniformly distributed integers within whatever range you specify — every value between the minimum and maximum is equally likely.
Tips & Considerations
- The minimum and maximum are both inclusive — a range of 1 to 6 can return 1 or 6.
- If you enter the maximum below the minimum, the tool swaps them automatically.
- Results can repeat. For a draw with no repeats — like picking unique winners — you need sampling without replacement, which this tool does not do.
Frequently Asked Questions
Is this suitable for security or cryptography?
No. It uses Math.random(), which is fast but not cryptographically secure. For tokens, keys, or anything security-sensitive, use a cryptographic random generator.
Are the numbers truly random?
They are pseudo-random — produced by a deterministic algorithm that is statistically uniform and unpredictable enough for games, testing, and sampling.
Can I get the same number twice?
Yes. Each number is drawn independently, so duplicates are possible and expected, especially over a small range.
What does the Random Number Generator compute?
The Random Number Generator takes 3 input values and returns 1 result. Generate random integers within a range — for testing, sampling, giveaways, and simulations.