Draw

Drag the handle round to open the wedge, or use the arrow keys.

What this measures

Most tests of this kind show you a chart and ask for a number. This one runs the other way: it gives you the number and asks for the picture. That is the harder direction and the more useful one here, because it is what a wheel does — a wheel is a proportion someone has already drawn, and its honesty is the fact that the wedge and the odds are the same thing.

The edge you measure from is put somewhere different every round, and that is the part doing the work. Fixed at twelve o'clock the task stops being estimation almost immediately: you find the quarter and the half by the clock face and read off the rest. Put the edge at four minutes past eight and there is nothing to read off. What is left is whatever sense of proportion you actually have.

A minute’s exercise, not a test

Nobody is grading this and there is no score to beat. Judging a proportion by eye is a small, specific skill, and like most small specific skills it sharpens with a bit of practice and dulls without any — a few rounds now and then is genuinely a decent workout for the part of your eye that reads charts, maps and the size of one thing against another.

It also costs nothing, needs no account, and works on a phone or a tablet as well as it does on a laptop. If you come back another day the page will still remember how your last few tries went.

The line about which way you lean

After a few rounds the page starts keeping a note of the average direction of your misses — whether the wedges you draw tend to come out bigger or smaller than the number asked for. It is stored in your own browser, it is never sent anywhere, and it is cleared by the reset beside it.

It is a remark, not a result. A handful of tries is a handful of tries, and the honest thing to say about a small number of them is that they lean one way so far. If you want to see what it takes before a run of anything means something, the fairness test is the same argument made with spins.

Why we do not tell you how you compare

There is no score against other people here, and there will not be one. TrueWedge is a static site with no server and no database, so there is nowhere for anyone's results to be collected even if we wanted them — which means any ranking on this page would have to be invented. A made-up distribution is exactly the kind of dishonesty this project exists to avoid, and it would be undetectable by the person it flattered.

For the same reason the page never tells you which way people in general lean. The research on how badly we read proportions is real and worth reading — it is collected in how we misjudge proportions — but almost all of it asks people to judge a shape and name a number, which is the opposite task to this one. The two are not each other's mirror, so borrowing a direction from one and claiming it for the other would be arithmetic we cannot stand behind.

Sharing a round

Share the picture makes an image of your result. On a phone that opens the usual share sheet; on a desktop it copies the image so you can paste it straight into a message, and where the browser will not allow that, it saves it instead.

Send the challenge passes on a link carrying the exact wedge you were given — the same number and the same starting edge — so whoever opens it is answering your round rather than one of their own. Their result is theirs; nothing travels back to you, and nothing is recorded anywhere.

The link also carries your own score, so the page greets whoever opens it with the number to beat. It is taken on trust — nothing checks it and nothing could — which is why the page says somebody claimed it rather than stating it as a fact.

WhatsApp, X and email are handed a line of text naming the percentage you were asked for, so the challenge reads as one before anybody clicks. Facebook is the exception: it will not take text or a picture from a page, and shows only what it reads off this one — so your score goes to your clipboard instead, ready to paste into the box it opens.