How much is N plates?

In the gym, a “plate” means a 45 lb plate, counted on one side of the bar. “Two plates” is a 45 lb bar with two 45s on each side: 45 + 4 × 45 = 225 lb. Each extra plate per side adds 90 lb. In kilos the same talk means 20 kg plates on a 20 kg bar, adding 40 kg a plate. With 25 kg plates it is 50 kg a plate, so two plates is 120 kg.

Total weight for 1 to 8 plates on each side
Plates each side	45 lb bar + 45s	20 kg bar + 20s
1	135 lb	60 kg
2	225 lb	100 kg
3	315 lb	140 kg
4	405 lb	180 kg
5	495 lb	220 kg
6	585 lb	260 kg
7	675 lb	300 kg
8	765 lb	340 kg

How many plates is that?

The other way round: the fewest plates per side for common weights on a 45 lb bar, using the plates most gyms have (45, 25, 10, 5 and 2.5). For any other weight or set of plates, type it into What I need above.

Plates per side for common weights on a 45 lb bar
Total	Each side
135 lb	45
185 lb	45 + 25
200 lb	45 + 25 + 5 + 2.5
215 lb	45 + 25 + 10 + 5
225 lb	2 × 45
250 lb	2 × 45 + 10 + 2.5
275 lb	2 × 45 + 25
300 lb	2 × 45 + 25 + 10 + 2.5
315 lb	3 × 45
350 lb	3 × 45 + 10 + 5 + 2.5
405 lb	4 × 45
500 lb	5 × 45 + 2.5

Questions

What is the difference between “What I have” and “What I need”?

What I have starts from the plates: pick your bar, tap the plates to add them to the bar, and read the total. What I need starts from a number: type the weight you want to lift and it works out which plates to put on each side. Switch between them with the toggle at the top of the calculator.

Does the total include the bar?

Yes. The total is the bar plus every plate on both sides. Pick the bar you are using first: 45, 35 or 15 lb, or 20, 15 or 10 kg. A standard men’s Olympic bar is 45 lb or 20 kg; the lighter bars are the common women’s and training bars.

Do I enter the plates for one side or both?

One side. Plates go on in matching pairs, so you tap what is on one side of the bar and the calculator doubles it. A 45 and a 25 on each side of a 45 lb bar shows as 185 lb: 45 for the bar plus 140 of plates.

What if my target weight cannot be made exactly?

The calculator says so and shows the nearest weights you can load, just below and just above the target, with the plates for each. This usually happens when the amount left after the bar does not split into something your plates can make: 137 lb on a 45 lb bar needs 46 per side, and no combination of standard plates adds up to 46.

Can I tell it which plates my gym has?

Yes. In What I need, deselect any plate you do not have and the calculator will only use the ones left. That matters for home gyms with a limited set, and the choice is remembered in your browser so you set it once.

Does it use the fewest plates?

Yes. When it works out what to load, it finds the combination with the fewest plates per side, not just the heaviest plate first. That distinction matters with unusual sets: with only 45s and 20s available, 60 per side is three 20s, which a heaviest-first approach would miss.

What about collars?

Collars are not included in the total. Spring clips and most plastic collars weigh a few ounces and are safely ignored. Competition collars weigh 2.5 kg each, so if you lift with those, add 5 kg (about 11 lb) to whatever the calculator shows.