Barbell Weight and Plate Calculator

Olympic Bar Weight

An Olympic bar weighs 20 kg (44.1 lb) and is 2.20 m (7.2 ft) long. The women’s bar weighs 15 kg (33.1 lb) and is 2.01 m (6.6 ft) long. The International Weightlifting Federation (IWF) recognizes only these two bars, and its rules of November 5, 2025 set their weight and length.

A bar sold as 45 lb is not the 20 kg bar. It weighs 20.4 kg, 0.9 lb more than the Olympic bar’s 44.1 lb.

To tell which Olympic bar you’re holding, look at where you grip it. The 20 kg bar is 28 mm (1.1 in) thick there, and the 15 kg bar is 25 mm (1 in). The sleeves, the two ends where the plates slide on, are 50 mm (2 in) on both.

In powerlifting (squat, bench press, deadlift), the bar weighs 20 kg too. The rulebook of the International Powerlifting Federation (IPF) gives 55.1 lb (25 kg) with its two collars, the 5.5 lb (2.5 kg) rings that lock the plates on.

An Olympic bar made for home gyms can match that weight and length without being certified. Decathlon’s weighs 20 kg and is 2.20 m long, and its product page says it isn’t approved for competition.

Smith Machine Bar Weight

The bar on a Smith machine has no standard weight. Many machines have a counterweight that lightens it, so makers list a starting weight: what you actually lift with no plates on, after the counterweight has taken its share. According to their spec sheets, it ranges from 0 to 45 lb depending on the model.

The starting weight isn’t always the weight of the bar itself. In 2013, Technogym wrote that the Multipower bar in its Selection line weighs 41.9 lb (19 kg) and that you lift only 17.6 lb (8 kg) of it.

When a spec sheet gives the bar’s weight without mentioning a counterweight, the table uses that number. Technogym’s page for the current Multipower describes a counterbalanced bar without giving a number. The 34 lb (15.5 kg) in the table is for a different model, the Element Multipower, and comes from its manual. Panatta’s HP Base has a 39.7 lb (18 kg) bar, but its spec sheet doesn’t say how much the counterweight takes off. On Panatta’s Counterbalanced model, the counterweight cancels out the bar’s weight, and you can disengage it.

In the calculator, choose “Other” and enter your machine’s starting weight. If your machine isn’t in the table, weigh its bar.

The Smith Machine at Your Gym

Gym chains name the brands they buy, not the model on the floor. Two European chains, for example: Basic-Fit says its equipment comes from Matrix or Technogym, and Fitness Park names Technogym and Hammer Strength for its machines.

So look for the brand and the model on your machine, then find it in the table above. If it isn’t there, weigh the bar. For a straight bar or an EZ bar, the name of the chain doesn’t tell you the weight either.

EZ Bar Weight

An EZ bar, also sold as an EZ curl bar or a curl bar, has no standard weight. On the seven spec sheets below, it ranges from 13.2 to 30 lb (6 to 13.6 kg). Look at the sleeves. With 28 or 30 mm (1.1 or 1.2 in) sleeves, an EZ bar weighs under 15.4 lb (7 kg). With 50 mm (2 in) sleeves, it weighs 16.5 to 30 lb (7.5 to 13.6 kg).

In the calculator, choose “Other” and enter the weight of yours.

Barbell Weight by Length

A straight bar doesn’t always weigh 20 kg or 45 lb. Shorter bars, and home bars with 28 or 30 mm sleeves, weigh 13.2 to 33.1 lb (6 to 15 kg) on the spec sheets below.

A technique bar, like the 10 kg (22 lb) ones from Eleiko and Rogue, is for learning an exercise before you move up to the 20 kg bar. The Decathlon links go to archived copies from 2025.

Trap Bar (Hex Bar) Weight

A trap bar, also called a hex bar, weighs more than a straight bar. Eleiko’s and Gorilla Sports’ weigh 55.1 lb (25 kg), and Rogue’s weighs 60 lb (27.2 kg).

Rogue’s SB-1 safety squat bar weighs 70 lb (31.8 kg), and its MG-3 multi-grip bar weighs 43 lb (19.5 kg).

How to Weigh a Barbell

Step on a bathroom scale and note your weight. Step back on with the bar in your hands. The difference is the weight of the bar.

It works for a Smith machine too. Set the scale under the machine, step on, unrack the empty bar, and hold it. Whatever the scale shows on top of your own weight is what you actually lift, counterweight included.

Do You Count the Bar and the Collars?

The weight of a barbell exercise is everything you lift: the bar and its plates. On a Smith machine, that’s the bar’s starting weight plus the plates.

Whether collars count depends on where you lift. In competition, the pair weighs 11 lb (5 kg) and counts toward the announced weight. For 80 kg on the 20 kg bar, the IWF loading chart puts a 25 kg plate, a 2.5 kg plate, and a 2.5 kg collar on each side: 20 + 2 × 30. In a gym, Eleiko’s spring collars weigh 1.1 lb (0.5 kg) a pair, and the calculator doesn’t count them.

For dumbbells and machines, the conventions are in the guide How to Log Sets, Reps and Weight.

How to Calculate the Plates for Each Side

Start with the weight you want, subtract the bar, and divide by two. That’s what goes on each side. For 185 lb with a 45 lb bar, (185 − 45) ÷ 2 = 70 lb, which is a 45 and a 25.

Plates go on heaviest first, with the biggest toward the inside. That’s the rule in weightlifting and powerlifting alike. The calculator uses as few plates as possible, heaviest first, from the ones you’ve left checked under “Plates at your gym.”

A weight doesn’t always come out even. If your smallest plates are 2.5 lb, the bar loads in 5 lb steps. There’s no way to load 187 lb, so the calculator gives the two closest weights, 185 and 190 lb. The same goes for the weights you get from the 1RM calculator and the RPE calculator: 168.8 lb loads as 165 or 170 lb.

135, 225, 315, and 405 lb in Kilograms

Pound plates usually come in 45, 35, 25, 10, 5, and 2.5 lb. A 45 lb bar with one, two, three, or four 45 lb plates on each side comes to 135, 225, 315, and 405 lb.

One pound is exactly 0.45359237 kg, and has been since July 1, 1959. So 135 lb is 61.2 kg, 225 lb is 102.1 kg, 315 lb is 142.9 kg, and 405 lb is 183.7 kg.

Load a 20 kg bar the same way with 20 kg plates and you get 60, 100, 140, and 180 kg. That’s why 135 lb isn’t 60 kg: a 45 lb plate is 20.4 kg, and so is a 45 lb bar, while a 20 kg bar is 44.1 lb.