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Plate Calculator

How this is calculated

There is no formula here to cite, only arithmetic — which is exactly why it is easy to get wrong at the rack. Subtract the bar from your target, halve what is left, and that is what goes on one side. The calculator then looks for the combination of plates that reaches that number with the fewest plates.

The search is the part worth explaining. The obvious approach is to grab the heaviest plate that still fits, then the next heaviest, and so on. On a full commercial set that happens to give the right answer every time. On a partial set it does not. If the only plates you have are 25s, 20s and 15s and you need 30 kg a side, taking the 25 leaves you 5 kg short, while two 15s hit it exactly. This calculator checks every combination, so unchecking the plates your gym does not stock still gives you a usable answer.

When the target cannot be reached at all, you get the closest weight below it and the size of the gap. That is more useful than a number quietly rounded off: a 1 kg shortfall on a warm-up set is noise, and the same shortfall on a heavy single is the difference between a rep and a miss.

Two things the calculator cannot know. Collars weigh something — competition collars are 2.5 kg for the pair, spring clips are close to nothing — so if yours are heavy, add them to the bar weight. And bars vary: 20 kg and 45 lb are standard, women's bars are 15 kg, and plenty of gym bars are whatever the manufacturer decided. Weigh yours once if you can.

The small plates deserve their own line. A pair of 1.25 kg plates moves the bar by 2.5 kg, and that is the smallest step most gyms allow at all. Without them the step doubles to 5 kg, which on a press is not a detail. Uncheck them and you can see how much coarser every answer becomes.