Random Number Generator

Introduction

Calq.’s Random Number Generator quickly picks a single integer between two values you choose. It’s ideal for games and classroom activities, simple simulations, picking a raffle winner, or selecting a random record for testing. The tool is pseudo-random, meaning it uses an algorithm to mimic randomness. It is not suitable for cryptographic or security-sensitive purposes. Both your minimum and maximum values are included in the possible outcomes.

How it works

1. Enter a minimum value (inclusive).
2. Enter a maximum value (inclusive).
3. Click Generate to receive one integer selected uniformly at random from the range.
4. Run it again any time you need another independent draw.

Inputs explained

• Minimum value (inclusive) - The smallest integer that can be returned. Use any whole number, including negatives.
• Maximum value (inclusive) - The largest integer that can be returned. Must be a whole number and at least as large as the minimum.

Results and interpretation

• Output - A single integer. Every integer between the minimum and maximum, including both endpoints, has the same chance of appearing.
• Uniformity - If the range contains N numbers, each has probability 1/N. Over many runs, the results should look evenly spread across the range, though small samples can show streaks.
• Repeats - Each click is an independent draw. The same number can appear again on subsequent runs.

Method and assumptions

• Distribution - The tool models a discrete uniform distribution over all integers from a to b. Number of outcomes N = b − a + 1. Probability of any specific k is 1/N.
• Expected value - Theoretical mean = (a + b) / 2.
• Variance - For N outcomes, variance = (N² − 1) / 12.
• Conversion from a base random source - Conceptually, an underlying uniform value in [0, 1) is scaled to the integer range using a method designed to avoid rounding bias. Endpoints are inclusive by design.
• Pseudo-randomness - Results come from a deterministic algorithm (a pseudo-random number generator). This is excellent for general use, games, and education but should not be used for cryptography, lotteries, or security tokens.

Domain-specific context

• Games and education - Simulate dice (1-6), coin flips (0-1 or 1-2), or randomize student order. Explain probability by showing that each integer has equal chance over time.
• Statistics and data - Draw a random record index, assign participants to groups, or select a day-of-month. For formal experiments, document your procedure and consider reproducibility needs.
• Software testing - Pick random IDs or offsets to spot-check data. For repeatable test cases, record outputs or use a fixed seed in your development environment. This web tool itself does not expose seeding.

Tips and strategies

• Set bounds carefully - Double-check that the minimum is less than or equal to the maximum. Watch out for off-by-one errors; both ends count.
• Choose the right range size - Larger ranges spread results more; small samples may look “clumpy” even when the process is fair.
• Integers only - Decimals are not accepted. If you need decimals, generate integers and scale them (e.g., divide by 10) outside the tool.
• Negative ranges - You can include negatives (for example, −10 to 10). The midpoint is still (a + b) / 2.
• Multiple unique picks - This tool returns one number per run. For draws “without replacement,” keep a list of numbers already chosen and exclude them in later runs.
• Quick fairness check - Run 100 times and tally frequencies. Expect some variation, but counts should be roughly similar. Over thousands of runs, averages approach the theoretical mean.

Example calculations

• Dice roll: Minimum = 1, Maximum = 6. Possible outcomes are 1, 2, 3, 4, 5, 6. Each has probability 1/6 ≈ 16.67%. Theoretical mean = (1 + 6) / 2 = 3.5.
• Three-digit number: Minimum = 100, Maximum = 999. There are N = 900 possible outcomes. Each has probability 1/900 ≈ 0.111%. Theoretical mean = (100 + 999) / 2 = 549.5.
• Negative to positive range: Minimum = −3, Maximum = 3. Outcomes = −3, −2, −1, 0, 1, 2, 3 (N = 7). Each has probability 1/7 ≈ 14.29%. Theoretical mean = 0.

Frequently asked questions

• Are the minimum and maximum included?
  Yes. Both endpoints are part of the possible results.

• Can I use negative numbers?
  Yes. You can set minimum and maximum to any integers, including negatives.

• What happens if the minimum is greater than the maximum?
  There is no valid range. Swap the values so that minimum ≤ maximum.

• Is this suitable for cryptography or security?
  No. The generator is pseudo-random and not appropriate for cryptographic keys, passwords, or secure lotteries.

• Why do I see repeats or streaks?
  Random processes naturally produce clusters. Each draw is independent; repeats are expected, especially in small samples.

• Can I generate multiple numbers at once or prevent duplicates?
  This page returns one integer per click. For multiple unique numbers, run several times and track previously drawn values.

Summary

Calq.’s Random Number Generator delivers a single, uniformly distributed integer from an inclusive range you choose. It is fast, simple, and ideal for games, teaching, sampling, and everyday decisions, but it is not designed for cryptographic use. Use the calculator above with your own minimum and maximum to generate your next random number.