Barbell Plate Calculator
Work out which plates go on each side of the bar for any target weight, using only the plates you own, with collars, kg or lb, and a warm-up ramp.
How to Use
- Choose kilograms or pounds, type the target weight, and pick the bar: 20 kg, 15 kg, 45 lb, 35 lb or a custom weight.
- Set the collars: none, competition collars (2.5 kg each, as the IPF and IWF rules require) or your own collar weight.
- Enter how many pairs of each plate you have. Leave a size at 0 if you don’t own it — the answer only uses plates that exist.
- Read the plates per side, heaviest first from the inside, on the drawing and in the readouts. If the weight can’t be made exactly you get the nearest weight below and above.
- Use the warm-up table for a ramp up to the work set, and Show Work for the arithmetic and the feasibility check.
Worked Example
A 100 kg squat. Take the 20 kg bar off: 100 − 20 = 80 kg of plates, so 40 kg a side. Heaviest first, a 25 leaves 15, and a 15 finishes it: 25 + 15. The same bar is 100 ÷ 0.45359237 = 220.46 lb.
When the heaviest plate is the wrong first choice. A home gym has one pair of 15s, two pairs of 10s, and a pair each of 2.5s and 1.25s. For 60 kg each side needs 20 kg. Taking the 15 first leaves 5 kg, and 2.5 + 1.25 only makes 3.75, so the calculator checks before it commits, skips the 15 and loads 10 + 10.
The common mistake: forgetting the collars. In a meet the collars weigh 2.5 kg each. For a 182.5 kg attempt each side needs (182.5 − 20 − 5) ÷ 2 = 78.75 kg: three 25s, a 2.5 and a 1.25. Loading (182.5 − 20) ÷ 2 = 81.25 kg a side and then adding the collars puts 187.5 kg on the bar — 5 kg too much.
Show Work
Formulas
What the Rulebooks Say About Bars and Plates
Both international federations publish exact equipment rules. The International Weightlifting Federation’s Technical and Competition Rules & Regulations (2025 edition, §3.3.3) specify a 20 kg bar for men and a 15 kg bar for women, two collars of 2.5 kg each, and a colour for every competition disc: 25 kg red, 20 kg blue, 15 kg yellow, 10 kg green and 5 kg white, with the small change discs repeating the sequence (2.5 kg red, 2 kg blue, 1.5 kg yellow, 1 kg green, 0.5 kg white). Discs are loaded heaviest first, lighter ones towards the outside.
The International Powerlifting Federation’s Technical Rulebook (effective 1 March 2026, §2.3–2.4) sets the bar and collars at 25 kg together, with collars of 2.5 kg each. It requires every disc to be within 0.25 % or 10 g of its face value, limits discs of 20 kg and over to 6 cm thick and those of 15 kg and under to 3 cm, caps the diameter at 45 cm, and fixes colours only for the big three: 25 kg red, 20 kg blue and 15 kg yellow; 10 kg and lighter may be any colour. The first and heaviest discs go on face in and the rest face out, so the referees can read every weight.
Pound plates follow no international rule. The familiar 45 lb plate is 20.41 kg, which is why a gym “plate” total in pounds never converts to a round number of kilograms.
About This Tool
This calculator loads a bar the way a lifter does, heaviest plate first, but checks every choice against the plates you actually own, so it never suggests a 15 when the rest of the side can’t then be made. It handles kilograms and pounds, men’s, women’s and custom bars, and competition or custom collars. When a weight can’t be loaded exactly it says why and shows the nearest weights below and above. The drawing colours kilogram plates by the IWF competition code, and a warm-up ramp works up to the target in loadable steps.
Everything runs in your browser; nothing you enter is sent anywhere. For general information only — not medical advice. Talk to a doctor or other qualified professional about your own health.
Related tools: One-Rep Max (1RM) Calculator, RPE & RIR Calculator, and Wilks & DOTS Powerlifting Score Calculator.
Frequently Asked Questions
How do I work out the plates for each side of the bar?
Take the bar (and collars) off the target and halve what is left. 100 kg on a 20 kg bar leaves 80 kg, so 40 kg a side: one 25 and one 15. 225 lb on a 45 lb bar leaves 180 lb, so 90 lb a side: two 45 lb plates.
How much does a barbell weigh?
A men’s weightlifting bar weighs 20 kg and a women’s bar 15 kg under the IWF rules. In IPF powerlifting the bar and collars together weigh 25 kg. The common 45 lb bar is 45 × 0.45359237 = 20.41 kg, close to but not the same as a 20 kg bar.
Do collars count towards the weight?
Yes. Competition collars weigh 2.5 kg each under both the IPF and IWF rules, so a pair adds 5 kg. For a 182.5 kg attempt each side needs (182.5 − 20 − 5) ÷ 2 = 78.75 kg — three 25s, a 2.5 and a 1.25 — not the 81.25 kg you would load without counting them.
What do the plate colours mean?
The IWF colour code is 25 kg red, 20 kg blue, 15 kg yellow, 10 kg green and 5 kg white, with smaller change plates in the same order (2.5 kg red, 0.5 kg white). The IPF fixes only 25 kg red, 20 kg blue and 15 kg yellow; 10 kg and lighter may be any colour. Pound plates have no colour code.
Why can’t my target weight be loaded?
Every plate goes on in pairs, so the total can only change in steps of twice the smallest plate. With one pair of 0.5 kg plates, 97 kg on a 20 kg bar needs 38.5 kg a side, which those plates can’t make; the nearest loads are 96 kg (25 + 10 + 2.5 + 0.5) and 97.5 kg (25 + 10 + 2.5 + 1.25).
How do I use the Barbell Plate Calculator?
Simply type your numbers and read the result, which refreshes the instant you change something. There is nothing to submit and nothing to wait for.
Does it cost anything or need an account?
No. The tool is completely free, there is no account to create, and it keeps working offline after the page first loads.
Is anything I type uploaded?
No. The tool works entirely on your device, so the values you enter never leave your browser.
Common Use Cases
Loading a competition attempt
182.5 kg with 2.5 kg collars is 3 × 25 + 2.5 + 1.25 kg a side — 78.75 kg each side, heaviest plates innermost.
A home gym with odd plates
With one pair of 15s and two pairs of 10s, 60 kg needs 20 kg a side: a 15 would leave 5 kg you can’t make, so it loads 10 + 10.
Planning warm-up sets
For a 100 kg work set the ramp is 40 kg (10 a side), 60 kg (20), 75 kg (25 + 2.5) and 85 kg (25 + 5 + 2.5).
Pound plates
225 lb is two 45 lb plates a side on a 45 lb bar, which is 102.06 kg.
A 15 kg bar
62.5 kg on a 15 kg bar needs 23.75 kg a side: 20 + 2.5 + 1.25.
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