Plate Calculator

By Jack Kyle — Jack Kyle writes about strength training and lifting math — calculators, programming and standards — with a focus on honest numbers and practical guidance.

Estimates only — see our Disclaimer

What this calculator does

You have 97.5 kg on the programme and a rack full of plates — and you stand there doing subtraction in your head while the bar waits. This calculator removes that pause. Enter your target weight and your bar weight, and it tells you exactly which plates to put on each side of the bar, largest first, so you can load once and lift.

It is built for anyone who trains with a barbell and a programme written in numbers: percentage work, 5/3/1 sets, warm-up ladders, or a session where the load changes every set. It is also useful when you switch gyms and the plate selection changes, or when you train in a unit you do not think in — the unit switch converts your entered numbers, so a kg session can be re-planned in lb without redoing the maths. Pick your target, read the per-side list, load it, and go. The maths stays out of the way of the session.

How it works

The maths is simple division, shown openly so you can check it:

1. Subtract the bar weight from the target weight.
2. Divide the remainder by two — that is what each side must carry.
3. Fill that per-side weight with the largest plates first, then the next size down, until the side is exact.

Example: target 100 kg, bar 20 kg. Remainder 80 kg, so 40 kg per side. The calculator fills 40 kg per side as 25 + 10 + 5.

Units. The unit switch on this calculator DOES convert numbers you have already entered — switching between kg and lb re-expresses your target and bar weight in the new unit. (This differs from the one rep max calculator, where the unit switch changes the label only and does not convert entered numbers.)

Limits to know. The calculator can only use the plate sizes it is given. If your gym lacks a size the result calls for, the exact target may not be loadable — round to the nearest loadable weight and note the difference. It counts plates, not collars: if your collars are heavy, add their weight to the bar weight you enter. It also assumes the plates are true to their stamped weight; worn or uncalibrated plates can be off by more than the maths suggests. For why estimated numbers and real bars sometimes disagree, read why 1RM calculators give different answers.

How to load the bar

1. Enter the target weight and the bar weight.
2. The calculator subtracts the bar weight from the target and divides the remainder by two — that is what each side must carry.
3. Load the per-side list largest plates first, then the next size down, until the side is exact.
4. If your collars are heavy, add their weight to the bar weight you entered.
5. If the exact target is not loadable from your gym’s plates, round to the nearest loadable weight and record what you actually loaded.

Frequently asked questions

How does the plate calculator handle the bar weight?

It subtracts the bar weight you enter from the target weight, then splits the remainder across two sides. A 20 kg bar and a 100 kg target means 80 kg of plates, or 40 kg per side. If your bar is 15 kg or 25 lb, enter that number — the calculator does not assume a bar weight for you.

What if my gym does not have a plate the plan calls for?

Then the exact target is not loadable with the plates available. Load the closest combination you can make and record what you actually lifted. A 2.5 kg difference on a top set is a real difference — better to log the true load than to pretend you hit the planned number.

Can I mix kg and lb plates?

You can, but the maths gets messy and the total gets hard to verify. This calculator works in one unit at a time. If your gym has both, pick one unit for the session and convert the target first, then load only plates in that unit.

Why does it show plates per side, not the total?

Because that is how you load a bar. A total plate list invites the common mistake of putting the full list on one side. Per-side lists keep both sides equal, which is what matters when you step up to the bar.

Does it include collars?

No. Collars vary too much in weight to assume. If you use competition collars at 2.5 kg each, add 5 kg to the bar weight you enter. If you use light spring collars, their weight is small enough to ignore for most sessions — but on a precision day, weigh them once and add them in.

More calculators: find every Barloadr tool on the Barloadr homepage.