Strength
How to load a barbell: bar weights, plates and the math
Loading a barbell sounds trivial until you are halfway through a warm-up, doing sums between sets, or training in a gym that mixes kilogram and pound plates. This guide covers what the bar weighs, the one formula you need, and the mistakes that leave you lifting the wrong weight.
How much does a barbell weigh?
| Bar | Weight | Notes |
|---|---|---|
| Men’s Olympic bar | 20 kg (44.1 lb) | Standard in most gyms and competitions |
| Women’s Olympic bar | 15 kg (33.1 lb) | Thinner grip, slightly shorter |
| US standard bar | 45 lb (20.4 kg) | The usual bar in pound-based gyms |
| Technique bar | Often 5–15 kg | Varies a lot — check the label |
| Trap or specialty bar | Often 20–30 kg | Varies by brand — check the label |
If a bar isn’t marked, don’t guess from its size. Specialty bars in particular vary widely, and a 5 kg mistake in the bar is a 5 kg mistake in every set.
The plates-per-side formula
Weight per side = (target − bar − collars) ÷ 2
Then build that weight from the heaviest plates down. For a 100 kg squat on a 20 kg bar: (100 − 20) ÷ 2 = 40 kg per side, which is a 25 kg plate plus a 15 kg plate.
| Target (20 kg bar) | Per side | Plates per side |
|---|---|---|
| 60 kg | 20 kg | 20 |
| 100 kg | 40 kg | 25 + 15 |
| 140 kg | 60 kg | 25 + 25 + 10 |
| 180 kg | 80 kg | 25 + 25 + 25 + 5 |
In pound gyms the milestones are easy to remember because 45 lb plates stack neatly on a 45 lb bar: 135 is one plate a side, 225 is two, 315 is three and 405 is four.
Plate colors
Competition plates follow a color code so judges and lifters can read the bar at a glance: 25 kg red, 20 kg blue, 15 kg yellow and 10 kg green. Smaller change plates vary between federations and brands. Many gyms use plain black or grey plates, so read the number rather than trusting the color.
Don’t forget collars
Spring clips weigh almost nothing, but competition collars weigh 2.5 kg each — 5 kg for the pair. If you train with them, include them in the sum, or your 200 kg deadlift is really 205 kg.
Mixing kilograms and pounds
A 20 kg plate is 44.1 lb, not 45, and a 45 lb plate is 20.4 kg, not 20. The difference is small for one plate but adds up: a 20 kg bar with two 20 kg plates is 60 kg, or 132.3 lb — not the 135 lb you might assume. When a gym mixes plate types, convert everything to one unit before you load.
Loading tips
- Put the heaviest plates on first, closest to the middle, so the load is stable.
- Load and unload alternately — one plate per side — so the bar doesn’t tip in the rack.
- Push plates all the way in and use collars for anything heavy.
- If your plates can’t make the exact number, round to the nearest weight you can load and note it in your log.
General fitness information, not medical advice. Check with a doctor or qualified coach before major changes to diet, supplements or training.