How it works

One private number from each person, one shared number back. Here is exactly what happens in between, and what is kept afterwards.

The flow

1. Someone creates a room. They enter what the money is for, the currency, how many people are involved, and their own comfortable maximum per person. That counts as the first answer.
2. They share the link. There is nothing to install and no account to make. Anyone with the link can answer once from their browser.
3. Everyone answers privately. One number each. The page shows how many answers are in, never whose, never what.
4. The result appears automatically. When the expected number of answers is reached, the room computes the group-safe cap and shows it to everyone with the link.
5. The raw answers are deleted. In the same operation that publishes the cap, every individual amount is removed from the database.

The decision rule

The published cap is the lowest comfortable maximum submitted, rounded down. It is never an average, a midpoint, a majority choice or a recommendation, and it can never be higher than what somebody said they could live with.

If five people submit 500, 450, 300, 600 and 380, the lowest is 300 and the published cap is 300. If they submit 500, 450, 317, 600 and 380, the lowest is 317 and the published cap is 300, rounded down to the nearest 20.

How rounding works

The published cap is rounded down to a round-looking step of about 5% of the lowest amount submitted: to the nearest 20 in the low hundreds, the nearest 250 in the low thousands, and so on. The step is always one of 1, 2, 2.5 or 5 followed by zeroes, because those are the numbers people actually plan around.

Rounding is always downward, never upward. It keeps the number usable and it blurs the exact figure, so the lowest answer is a little less identifiable than a precise number would be.

Raising your own answer can never lower the group’s cap. The step sizes change only at points that are themselves a multiple of the new step, so the published figure only ever moves in the same direction as the answers behind it.

Group size

A room needs at least 3 people and takes up to 30. The minimum is not arbitrary: with two people, publishing the lower of two numbers tells each of them what the other one said. Three is the smallest group where the result genuinely does not identify anyone.

Even at three, be realistic. In a small group, someone who knows a lot about the others may still be able to guess whose number set the cap. This tool makes that harder. It cannot make it impossible, and we won’t claim it does.

Changing your mind

You can edit your own answer from the same browser at any time until the result appears. After that, nothing can be changed, because the raw answers are gone, including yours.

The organiser can raise the expected number of people if someone else joins the plan, reset the room (which deletes every answer and starts again), or delete the room outright. They cannot see any individual answer at any point.

What is kept, and for how long

• While the room is open: the title, the currency, the expected number of people, the number of answers received, and each answer as encrypted data.
• After the result: the title, the currency and the rounded cap. The individual answers no longer exist.
• Deletion: an unfinished room is deleted 7 days after it is created. A finished one is deleted 7 days after the result appears. The organiser can delete it sooner at any time.

The full detail, including what our infrastructure providers see, is on the privacy page.