The 1–60 range
Sixty is the number the Babylonians left us: sixty seconds, sixty minutes, 360 degrees in a circle. They counted in base 60, and four thousand years later your watch still does.
It stuck because it divides so well. Sixty has twelve divisors, more than any smaller number, so it breaks into halves, thirds, quarters, fifths, sixths, tenths, twelfths, fifteenths, twentieths and thirtieths with nothing left over.
In practice a 1–60 draw usually means a minute, a second, an interval or a slot in an hour-long grid.
- 1 to 60, both included
- 60 whole numbers
- 1.67%, exactly 1 in 60
- 1 to 10 numbers per draw
- None inside a multi-number draw
- Every draw gets a link that replays it
What a 1–60 draw is for
- Picking a random minute or second for an interval timer
- Choosing a starting point in a sixty-minute recording
- Drawing a slot from an hour split into one-minute blocks
- Selecting one of sixty numbered lots or tickets
- Setting a random rest length in seconds during a workout
How the randomness works
Every tap calls crypto.getRandomValues, the browser's cryptographic generator, and asks it for one unsigned 32-bit value. That lands somewhere between 0 and 4,294,967,295, and it then has to be folded down to the 60 numbers in this range.
Folding it down with a plain remainder is where most generators go wrong, an error known as modulo bias. 60 does not divide 4,294,967,296 evenly: 16 values are left over at the top, and wrapping them around would make the first 16 numbers in the range fractionally likelier than the rest. This tool throws away any raw value at or above the last exact multiple of 60 and draws a fresh one instead. That is rejection sampling. It fires about 1 in 268,435,456 draws, and it is the difference between 1.67% exactly and 1.67% approximately.
Ask for more than one number and the tool keeps drawing until it holds that many distinct values, then sorts them ascending. Nothing is seeded, nothing is sent anywhere, and each draw is independent of the one before it. The roll history under the tool lives in your browser's local storage, where the clear button empties it. The daily lucky numbers elsewhere on this site work the opposite way on purpose: they use a seeded generator so the same date always returns the same set. How random is random sets the two side by side.
One point six seven percent is a repeating decimal, and that is a hint that 60 does not divide the draw space cleanly. Sixteen values are left over and get discarded rather than folded back in. The practical effect of doing it that way is nil; the point is that the guarantee stays exact instead of nearly exact. One quirk to remember if you are drawing a duration: 1–60 excludes zero, so no result will ever tell you to wait no time at all.
- crypto.getRandomValues, the browser's cryptographic generator
- One unsigned 32-bit value, sometimes more
- Rejection sampling onto 60 slots
- 16 of 4,294,967,296 raw values, redrawn
- No. These tools are never seeded
- Your browser. No server ever sees a draw
1–60 — frequently asked
Draw once and read the result as minutes or seconds. If zero should be a possible answer, set the From field to 0 on the main number picker and the range becomes 0–60.
Because Babylonian astronomers counted in sixties, and Greek and Islamic astronomers inherited the system for measuring angles and time. Sixty divides into more whole parts than any smaller number, which mattered when fractions had to be done by hand.
You can draw a start minute, though a genuine shuffle needs every track to be equally likely, not every minute. Long tracks would win too often.