Random Number Calculator: Pick Numbers Within a Range
A random number calculator selects whole numbers between a minimum and maximum you choose. Use it to pick a number for a game, create sample values, or make a simple random choice from a numbered list. You can generate one number or up to 100 numbers at once.
How to generate random numbers
- Enter the smallest and largest allowed whole numbers.
- Choose a quantity from 1 to 100.
- Select whether duplicate values are allowed.
- Select Generate Random Numbers.
The minimum and maximum can be positive, negative, or zero. Each must be between −1,000,000,000 and 1,000,000,000, and the maximum must be at least the minimum. Decimal limits are not supported because the output consists of integers.
Are the minimum and maximum included?
Yes. A range from 1 to 10 can produce any integer from 1 through 10, including both endpoints. The number of possible values is maximum − minimum + 1. For −3 through 3, the seven possible values are −3, −2, −1, 0, 1, 2, and 3.
If the minimum and maximum are equal, there is only one possible value. A range from 7 to 7 always returns 7. With duplicates allowed, you can request that value multiple times.
Allow duplicates or generate unique numbers?
Allowing duplicates means every draw uses the full original range. A value may appear more than once, and a new batch may repeat numbers from an earlier batch. Repetition is a valid random outcome.
Unique mode selects without replacement, so each number appears at most once within a generated batch. The requested quantity cannot exceed the number of values in the range. For example, 1 through 5 supports at most five unique numbers. Generating all five gives a random ordering of 1, 2, 3, 4, and 5.
Unique selection applies to the current batch. Generate Again starts a fresh selection, so values from earlier results may appear again.
How does random selection work?
The calculator obtains random values from your browser’s cryptographic random number generator. It uses rejection sampling to map those values to the selected range without the bias that simple remainder mapping can introduce.
With duplicates allowed, each draw has the same chance of selecting any value in the range. In a range of 1 to 10, each integer has a 1-in-10 chance on each draw. Unique mode instead draws from the remaining unselected values, using a partial shuffle.
Random does not mean evenly distributed in every small batch. Several similar numbers, consecutive values, or repeated values can occur. Generate Again creates a fresh draw; it does not guarantee a different result.
Examples of random number ranges
Dice-style draw: choose a minimum of 1, maximum of 6, and quantity of 1. Each result represents one of six possible values.
Numbered list: label ten items from 1 through 10, then generate a number in that range to select an item. To select three distinct items, request three numbers in unique mode.
Positive and negative values: use −20 through 20 to draw from 41 integers, including zero. For practice data, generate a batch with duplicates allowed.
Frequently asked questions
Can I generate negative numbers?
Yes. Use a negative minimum, a negative maximum, or a range that crosses zero. Both limits must be whole numbers within the supported range.
Why did the same number appear twice?
Duplicates are possible when every draw uses the full range. Choose unique mode to prevent repeats within one batch.
Can I generate decimal numbers?
No. This calculator generates integers. Enter whole-number limits and a whole-number quantity.
Why is my unique quantity rejected?
Your range contains fewer values than the quantity requested. Increase the range, reduce the quantity, or allow duplicates.
Does Reset generate another number?
No. Reset clears the result and restores the starting inputs: 1 through 100, one number, and duplicates allowed. Generate Again draws a fresh result using your current inputs.
Are the calculation inputs sent to a server?
The number generation runs in your browser. The calculator’s code does not send or store the entered limits or generated numbers.