Prototype · built with Claude

Barbell Maths

A plate calculator for people who'd rather lift than do mental arithmetic mid-set.

The idea

“I'm bad at maths. Every time I load a barbell, I end up on my phone's calculator working out which plates go on each side.”

So I made the calculator I wanted: enter a target weight, get the plates per side. I added warm-up percentages and tappable plates so I could keep track as I loaded the bar.

Made with Claude, tested at the gym

I described what I wanted, got a rough version working, then iterated from there. I tweaked the interactions and colour-coded the plates, then turned it into a standalone file I could keep on my phone between sets.

Have a go

Best on your phone — preferably at the gym.

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