The formula
How it works
Generate a random number in any range you choose. Set a minimum and maximum, pick whole numbers or decimals, and press Generate for a fresh value each time.
FAQ
Are the minimum and maximum included?
Yes. In whole-number mode every integer from the minimum to the maximum is equally likely, both ends included. In decimal mode the value can land anywhere in the range, so it may sit very close to either limit but effectively never exactly on the maximum.
Is this truly random?
It uses your browser’s built-in pseudo-random generator, which is more than random enough for games, draws, picking a winner or sampling. It is not designed for cryptography or security keys, which need a dedicated cryptographic generator, but for everyday “pick a number” tasks it is ideal.
Will I get the same number if I generate it again?
No. Each press of Generate draws a fresh, independent value, so getting the same number twice in a row is possible but no more likely than any other repeat.
Can the minimum be negative or larger than the maximum?
You can enter a negative minimum and the range works the same way. If you accidentally enter a minimum larger than the maximum, the calculator swaps them so the range is still valid.
How many decimal places can I choose?
You can set the decimal places from 0 up to 10. The generator scales a random value into your range and then rounds it to exactly that many places.
Can I generate more than one random number at once?
This tool returns one number per press of Generate. For multiple values, press it repeatedly, keeping in mind that repeated whole-number draws can occasionally produce duplicates unless you remove numbers from the range yourself.
Is it fair to use this for a giveaway or raffle?
Yes, as long as every entrant maps to a unique number in the range and the draw is done openly, since each value in the range has an equal chance of being chosen.
About the random number generator
This tool produces a random number within a range you define. You set the lowest and highest values, choose whether you want a whole number or a decimal, and press Generate for a new result on demand. It replaces slips of paper in a hat or rolling dice with a quick, unbiased pick — handy any time you need a fair, unpredictable number.
How to use it
Enter the minimum and maximum of your range, then choose whole numbers or decimals; if you pick decimals, set how many places you want. Press Generate to draw a number, and press it again for another. For example, a range of 1 to 100 in whole-number mode returns any integer from 1 through 100, each with an equal chance.
The formula
A base random value between 0 and 1 is scaled into your range as . For whole numbers the result is rounded down into equal-width buckets so that every integer from the minimum to the maximum is equally likely. For decimals the scaled value is simply rounded to the number of places you asked for.
Where it is used
People use it to run raffles and giveaways, pick a winner from a numbered list, choose a random question or task, assign turns, or sample items for a spot check. Teachers use it to call on students at random, and gamers use it as a substitute for dice or spinners. Anywhere fairness depends on nobody being able to predict or influence the outcome, a random number does the job.