About Perfect Balance

I built Perfect Balance to make a game out of judging weight by eye, with real objects, real weights and a scale that settles it with real physics.

The game

Each day there's a new puzzle of five rounds, the same for everyone. Every round puts one thing on the left pan and gives you a shelf of everyday objects for the right. Stack up what you think weighs the same, lock it in, and the scale lets go. Land within 3% light or 4% heavy and the round's yours.

There's also Freeplay, with rules you can change: a difficulty from Easy to Expert, a limit on how many things you can use, endless rounds, or a theme.

Where the weights come from

Every object you're asked to match has its weight from a standards body, a manufacturer, a sports governing body, a government database or a published study, checked against a second source. Fruit and veg vary, so for those I've used the average of two sources that agree within 10%.

The full list, with every source quoted, is in the game's catalogue on GitHub.

How it's made

The scene is drawn with three.js, and the physics is Jolt, compiled to WebAssembly and running in its own thread, so a pile of tins really can slide off a pan. Each round is generated from a seed with its answer built first, so there's always a way to win.

The code is open source under the MIT licence, on GitHub. The models and fonts are other people's work, listed on the Credits page.

Get in touch

If something breaks, or a weight seems wrong, open an issue on GitHub and I'll take a look. For a weight, tell me where you found yours.