What Are the Real Odds on a Wheel with 10 Names?

Start with the wheel in front of you

You have ten names on a wheel and need to explain whether everyone has the same chance. The useful starting point is to count entries, not just people. If each of the ten lines contains a different person’s name exactly once, each line has the same chance of being selected. A particular person’s chance on one spin is one out of ten, or 10%.

Spin the Wheel lets you enter names or other options, one per line. Its selection uses crypto.getRandomValues with rejection sampling, and the result is chosen before the animation. The animation is for presentation; it does not determine who wins. The equal-chance explanation applies when the entries on the wheel are equally represented.

Translate one-in-ten into a percentage

For an equally represented list, divide the number of entries for the person you are asking about by the total number of entries. With one line for a person and ten lines overall, that fraction is one tenth. Multiply the fraction by 100 to express it as a percentage: 10%. This describes the chance on a single spin, not a promise about what will happen.

A fair random selection can still produce a result that feels surprising. One person could be selected on the first spin, even though each person began with the same chance. Equal probability describes the setup before the draw; it does not mean the wheel must take turns or produce a balanced-looking sequence.

When the wheel stays unchanged, spins are independent

If you leave all ten entries on the wheel, a new spin starts with the same options and the same one-in-ten chance for each name. Under those conditions, the next spin does not become more or less likely to select a particular name because of the previous result. The spins are independent: the earlier result does not change the entry list or the next spin’s odds.

For example, the chance that one particular name is selected on each of two consecutive spins is the chance on the first spin multiplied by the chance on the next spin: one tenth times one tenth, or one hundredth. That is 1%. This is the chance of that same named entry being selected both times, not the chance that someone will be selected on each spin. Someone is selected on every completed spin.

Removing winners changes the next spin

If you turn on the option to remove the winner after each spin, the list changes. After one winner is removed from ten entries, nine remain. Each remaining entry then has a one-in-nine chance on the next spin, about 11.1%. After another winner is removed, eight entries remain, and each remaining entry has a one-in-eight chance, or 12.5%.

Those are conditional chances: they describe the next spin given that the listed entries are still on the wheel. A name already removed cannot be selected again. This is sampling without replacement, so the odds change as the list shrinks. It is different from leaving the list intact, where each spin keeps the original one-in-ten chance for each entry.

Check for duplicate lines before you spin

The wheel treats each line as an entry, and duplicate lines add weight. If one person’s name appears on two lines in a ten-line list while other names appear once, that person has two of the ten entries. Their chance is 20%, not the one-entry chance of 10%. This may be intentional—for example, if you want some options to have extra weight—but it is not an equal chance per person.

Before using the wheel to make a choice, scan the list for accidental repeats, spelling differences, or blank lines that might represent options you did not mean to include. If every person should have the same chance, give each person one entry. If you want weighted chances, make the weighting deliberate and explain how the list is set up.

Make the result easy to follow

For a classroom, meeting, or party, say whether winners will be removed before the first spin. That small choice tells everyone whether the odds stay fixed or change after each result. You can also set a wheel title, choose a color theme, adjust the spin duration, or use fullscreen for a projector or stream. Results history can help you refer back to earlier outcomes.

The list is saved only in the browser. Share wheel places the list inside the link after the #, so the list is not uploaded. If you are using the wheel for a giveaway or raffle, rules vary; check the rules that apply to your situation.

When you are ready, enter the names one per line, check for duplicates, choose whether winners should be removed, and try Spin the Wheel.