A barbell plate calculator that uses the plates you actually have
Doing plate maths between sets is how people end up lifting 5 kg more on one side than the other. This barbell plate calculator tells you exactly which plates to put on each side of the bar for any target weight, in kilograms or pounds. Choose the bar — a 20 kg or 15 kg Olympic bar, or a 45 lb or 35 lb bar — say whether you use collars, and the answer appears instantly, with a drawing of the loaded bar.
Unlike a simple “divide by two” plate calculator, it works from your own inventory. Tell it how many of each plate your gym or garage has, and it finds the combination with the fewest plates — or, when a weight cannot be made, offers the nearest loadable weights above and below. It also builds a warm-up ramp and can add up a loaded bar in reverse.
How to use the Barbell Plate Calculator
- Pick kg or lb, then your Bar and Collars. Choose “Other bar weight” for EZ, trap or specialty bars.
- Type the Target weight — the total including the bar — or use the − and + buttons.
- Read the plates for each side, heaviest first. The drawing shows the order from the centre of the bar outwards.
- Open Your plates and set how many of each plate you have per side; the calculator never uses plates you do not own.
- Use the Warm-up sets table to ramp up, or switch to Add up the bar to total a bar someone else loaded.
Barbell Plate Calculator features
Exact, not greedy
A search over your plates finds a real solution when the simple “biggest plate first” method fails — for example 30 kg per side from 25s and 15s is 15 + 15.
kg and lb
Metric plates from 25 kg to 0.25 kg and pound plates from 55 lb to 1.25 lb, with the total converted to the other unit.
IWF colours
Kilogram plates are drawn in the official competition colours, so the picture matches the bar in front of you.
Nearest loadable weight
If the target cannot be made, one tap switches to the closest weight below or above.
Warm-up ramp
Empty bar, 40, 55, 70 and 85% of your work set, each rounded down to something you can load.
Reverse mode
Count the plates on one side and get the bar’s total in both units.
How the plates per side are worked out
Plates per side = (target − bar − both collars) ÷ 2. For 100 kg on a 20 kg bar without collars: (100 − 20) ÷ 2 = 40 kg per side, loaded as 25 + 15. With 2.5 kg competition collars, 142.5 kg becomes (142.5 − 20 − 5) ÷ 2 = 58.75 kg per side: 25 + 25 + 5 + 2.5 + 1.25.
The International Weightlifting Federation’s rule book (Technical and Competition Rules & Regulations 2025, rule 3.3.3.11) says the heaviest discs go on first and lighter discs follow in descending order towards the end of the sleeve; the calculator lists and draws them that way.
Standard bars, collars and plate colours
From the IWF rules: a men’s bar weighs 20 kg and a women’s bar 15 kg (rules 3.3.3.3–3.3.3.4), each collar weighs 2.5 kg (3.3.3.8), and competition discs are colour-coded (3.3.3.6). Typical gym pound bars weigh 45 lb (20.4 kg) or 35 lb; pound plates have no international colour code, so they are drawn dark.
| Disc | IWF colour | Small disc | Colour |
|---|---|---|---|
| 25 kg | Red | 2.5 kg | Red |
| 20 kg | Blue | 2 kg | Blue |
| 15 kg | Yellow | 1.5 kg | Yellow |
| 10 kg | Green | 1 kg | Green |
| 5 kg | White | 0.5 kg | White |
Loading tips
- Check the bar. Many gym bars are 15 kg, 18 kg or 25 lb, not the full 20 kg. Weigh it once and use “Other bar weight”.
- Count the collars when they are heavy. Spring clips weigh only a few grams; competition collars weigh 2.5 kg each.
- Mixing kg and lb plates works if you convert first: 1 lb = 0.4536 kg. The weight converter helps.
- Working from a percentage of your best lift? Find your training maxes with the one rep max calculator, then load them here.
Barbell Plate Calculator FAQ
How do I calculate plates per side?
Subtract the bar weight and the collars from your target, then divide by two. 100 kg on a 20 kg bar is 40 kg per side — a 25 and a 15. The barbell plate calculator does this and picks plates from your own set.
How much does an Olympic bar weigh?
Under the IWF rules a men’s bar is 20 kg and a women’s bar is 15 kg. In pound gyms the standard bar is 45 lb (about 20.4 kg). Technique and EZ bars are lighter — check the bar or weigh it.
What weight is 225 lb in plates?
On a 45 lb bar, 225 lb is 90 lb per side: two 45 lb plates on each side — the classic “two plates”. 315 lb is three 45s per side and 405 lb four.
Why can’t my weight be loaded exactly?
Your smallest plate pair sets the step: with 1.25 kg plates you can only change the total in 2.5 kg steps. The calculator then offers the nearest weights you can make. Fractional plates of 0.25 or 0.5 kg give finer steps.
Should I count the collars?
Count them if they have meaningful weight. Competition collars are 2.5 kg each, so they add 5 kg to the bar; light spring clips can be ignored.
What do the plate colours mean?
In weightlifting, kilogram discs are colour-coded: 25 kg red, 20 kg blue, 15 kg yellow, 10 kg green and 5 kg white, with the 2.5–0.5 kg change plates repeating that order. Pound plates do not follow a standard.