Barbell Plate Calculator
Enter the weight you want on the bar and Herculog works out exactly which plates to slide on each side — no mental math mid-workout, no half-loaded bars. Works in kilograms or pounds, with any bar.
How the calculator works
Loading a barbell is a two-step sum, and the calculator does both instantly. First it subtracts the bar from your target, because the bar is already on the rack. Then it halves what's left — plates load evenly on both ends — and fills that per-side number with the largest plates first, working down to the smallest.
So a 100 kg target on a 20 kg bar leaves 80 kg of plates, or 40 kg per side: a 25 and a 15. The visual shows the loaded sleeve so you can check it against the real bar at a glance. If your plate set can't hit the number exactly, the calculator loads as close as it can and tells you how much you're short.
Standard plate and bar weights
The calculator uses the standard commercial plate sets. Most gyms have these; if yours is missing a size, just load to the nearest achievable number.
| Metric (kg) | Imperial (lb) |
|---|---|
| Bars: 20 (men's), 15 (women's), 10 (training) | Bars: 45 (men's), 35 (women's), 15 (training) |
| Plates: 25, 20, 15, 10, 5, 2.5, 1.25 | Plates: 45, 35, 25, 10, 5, 2.5 |
Kilogram plates follow the international colour code — 25 red, 20 blue, 15 yellow, 10 green — which is why competition platforms look the way they do. Pound plates vary more by brand.
Common barbell loads
A few loads every lifter memorizes eventually. Type any of them above to see the breakdown.
| Total | Bar | Per side |
|---|---|---|
| 135 lb | 45 lb | One 45 |
| 225 lb | 45 lb | Two 45s |
| 315 lb | 45 lb | Three 45s |
| 60 kg | 20 kg | One 20 |
| 100 kg | 20 kg | 25 + 15 |
| 140 kg | 20 kg | Two 25s + 10 |
Loading tips
- Load biggest-first, against the collar. The heaviest plate sits nearest the middle so the bar stays balanced and the smaller plates don't bend around it.
- Always use collars for heavy or overhead work. A shifting plate mid-rep is how bars tip. The clip weight is small enough to ignore in your math.
- Match both sides before you unrack. The calculator gives you the per-side load once — mirror it exactly.
- Can't hit the number? Round to the nearest loadable weight and let progressive overload do the rest over time. Micro-plates (1.25 kg or smaller) exist precisely for small jumps.
FAQ
How much does a standard barbell weigh?
The Olympic men's bar is 20 kg (45 lb); the women's bar is 15 kg (35 lb). Training bars are often 10–15 kg. Pick your bar above so it's subtracted correctly.
How do I calculate plates per side?
Subtract the bar from your target, then divide by two. 100 kg − 20 kg bar = 80 kg of plates = 40 kg per side. The calculator then fills that with the largest plates first.
What plates do I need for 225 lb?
Two 45 lb plates per side on a 45 lb bar — 90 lb of plates each end. One of the most common loads in any gym.
Does the calculator send my data anywhere?
No. It runs entirely in your browser — nothing is uploaded, stored, or tracked, in keeping with how Herculog does everything.
Once the bar is loaded, Herculog logs the set in seconds and remembers it — so next session your last weight is right there, and the app tells you when you've hit a new PR.
More free tools
Estimate a one-rep max, plan warmups, or dial effort with RPE — all in the browser, all private.