Enter a target weight and get exactly which plates to slide on each side — in kg or lb, with your gym's actual plate set.
The lift
Per side
25 + 15
100 kg total — 20 kg bar plus 40 kg a side.
Loading order — heaviest first, against the collar
25
15
How barbell plate math works
Plates load in pairs, one on each side, so the arithmetic is always the same three steps: subtract the bar, halve what's left, then fill that number with the largest plates that fit.
For 100 kg on a 20 kg bar: 100 − 20 = 80 kg of plates, 40 kg per side, which is a 25 and a 15. For 225 lb on a 45 lb bar: 225 − 45 = 180, 90 per side, which is two 45s. That second one is worth memorising — in pounds, every plate pair adds 90 lb, so the familiar milestones (135, 225, 315, 405) are just the bar plus one, two, three or four pairs of 45s.
The jumps you can actually make
Your smallest possible increment is twice your smallest plate. With 1.25 kg plates that's 2.5 kg; with only 2.5 kg plates it's 5 kg. This matters more than it sounds. On a 60 kg bench press, a 5 kg jump is an 8% increase — a big ask week to week. On a 200 kg deadlift the same jump is 2.5%, which is fine.
That asymmetry is why lighter lifters and smaller lifts stall first: the available jump is too large a fraction of the working weight. Micro plates (0.5 kg or 1 lb) solve it directly, and they're the cheapest progress you can buy.
Common loads worth knowing
Total
Per side (20 kg bar)
60 kg
20
80 kg
25 + 5
100 kg
25 + 15
120 kg
25 + 25
140 kg
25 + 25 + 10
180 kg
25 × 3 + 5
Beyond about 200 kg you'll run out of 25s at most gyms and start stacking smaller plates, which is where the calculator earns its keep — it always reaches for the largest plate that fits, so you get the shortest stack the bar allows.
A standard Olympic barbell is 20 kg (45 lb). Women's Olympic bars are 15 kg (35 lb) and 2 m long, technique bars are usually 10 kg, and specialty bars — safety squat, trap, cambered — run from 25 kg to over 30 kg. If you're not sure, weigh it: guessing wrong throws off every number in your log.
Do plates go on in a particular order?
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Heaviest first, closest to the collar. It keeps the load nearer the centre of the bar, which reduces whip and makes the bar easier to control — and it's the convention everyone else follows, so nobody has to strip your bar to work out what's on it.
What if my gym doesn't have the plates I need?
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Untick the missing sizes in the plate list above and the calculator re-solves with what you actually have, telling you how close it can get. If you're consistently short, a pair of 1.25 kg or 2.5 lb plates is the single best-value purchase for a home gym — it halves your smallest possible jump.
Are the plate colours standard?
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For calibrated competition plates, yes: red 25 kg, blue 20 kg, yellow 15 kg, green 10 kg. Most commercial gyms use black rubber bumpers or iron plates that ignore the convention entirely, so read the numbers rather than the colour.
Does the calculator handle machines and dumbbells?
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Set the bar to 'No bar' and it will split your target across two even sides — which is what you want for loadable dumbbells or plate-loaded machines with a pin on each side.
