Random Number Between 1 and 1000
This page draws a whole number from 1 to 1000 on load and on every press. All 1000 values are equally likely, so each one has a 0.1 percent chance of coming up.
1 to 1000 1
1000 possible values, each equally likely. Tick nothing and repeats can happen; that is what random means.
Do not use this as a code
A number from this page is not a secure random value. Do not use it as a PIN, a password, a voucher code, or a ticket number for a draw with money attached. It comes from your browser Math.random, which is predictable to anyone able to observe enough of its output. For anything where the outcome has value, use a generator built on crypto.getRandomValues or your operating system random device.
The odds across 1000 values
Each number is 0.1%, or 1 in 1000. That sounds like plenty of room, and it is not. Draw 38 numbers and there is a 50.9% chance two of them are identical. Ten draws already carry a 4.4% chance of a repeat, and twenty carry 17.4%. Underestimating collisions is the standard mistake with a range this size, and it is why ticket numbers are issued in sequence rather than drawn.
Filling the range is the slow half: seeing all 1000 values at least once takes about 7,486 draws on average.
Getting 1 to 1000 by hand
- Three ten-sided dice. Read them as hundreds, tens and units for 000 to 999, and call 000 a thousand. Exactly 1000 outcomes, exactly even.
- Ten coin flips. Heads 1, tails 0 gives 0 to 1023. Add 1, keep anything up to 1000, and discard the other 24 sequences, a re-flip just 2.3% of the time. Ten flips at once has its own page.
Narrower ranges sit on 1 to 100, and the parent random number generator takes any range you type.