Barbell Plate Calculator — Load the Bar Right

Methodology

The calculator solves a small but genuinely fiddly gym problem: which plates go on each side of the bar?

per-side load = (target weight − bar weight) ÷ 2

The tool then builds that per-side load from your available plates, heaviest first — the conventional way to load a bar. Where a simple heaviest-first pass would miss a valid combination (sparse racks create these cases: loading 30 kg per side from only 20s and 15s requires passing over the 20), the tool searches every combination your inventory allows, so if a load can be built, it will be found.

When your exact target is impossible with the plates available, the calculator returns the nearest achievable weight, above or below, with ties resolved to the lighter load. The default inventory follows standard metric plate denominations (25 / 20 / 15 / 10 / 5 / 2.5 / 1.25 kg, as in the IPF technical rules), and any change you make to it is remembered on this device.

Interpreting your result

The headline is the per-side stack, listed in the order you'd slide the plates on. "Total" is what the bar will actually weigh — check it against your programme when the tool reports a nearest-achievable load rather than an exact one.

If your gym's smallest pair is 2.5 kg plates, your minimum jump is 5 kg on the bar — often too coarse for pressing progress. A pair of 1.25 kg (or microplates) is the cheapest training upgrade there is.

Limitations

Inventory counts are per side: two 25s per side means four 25 kg plates in the gym. Count what's actually free when the gym is busy.
Bar weights vary — worn or non-standard bars can be a kilogram or more off their nominal weight, and collars (typically 2.5 kg each in competition) are not included here.
Imperial plate sets aren't yet supported; kilogram racks only for now.

Sources

Pull the receipts — 1 cited source

FitTools · sources

01 IPF Technical Rules — standard competition plate denominations and bar weights

Every formula cited ✓

Frequently asked questions

How do I calculate which plates to put on a barbell?

Subtract the bar weight from your target, halve the remainder for the per-side load, then build that from the heaviest plates downwards. This calculator does exactly that, using only the plates you say your gym has.

How much does a barbell weigh?

A standard Olympic bar is 20 kg; common alternatives are 15 kg (frequently used as a women's competition bar) and 10 kg technique bars. Pick your bar in the calculator — it changes every answer.

What if my target weight can't be loaded exactly?

The tool shows the nearest weight your plates can actually make, whether just above or just below your target, and the stack to build it. When two loads are equally close it recommends the lighter one.

Can I use this with pounds?

The calculator works in kilograms, matching standard metric plate sets. Imperial plate inventories are planned alongside the site's wider imperial support.