How to load a barbell: plate maths made simple

Plate maths is simple, but it's annoying between sets when you're out of breath. Here's how to do it quickly, and how to stop doing it at all.

The formula

1. Take your target weight.
2. Subtract the bar: 20 kg or 45 lb for a standard Olympic bar.
3. Divide by two. That's what goes on each side.
4. Fill each side with the heaviest plates first.

Example in kg: 100 kg − 20 kg bar = 80 kg, so 40 kg a side: a 25 and a 15, or a 25, a 10 and a 5 if your gym has no 15s. In lb: 225 lb − 45 lb = 180 lb, so 90 lb a side: two 45s.

Bar weights

• Olympic bar: 20 kg or 45 lb.
• Women's Olympic bar: 15 kg or 35 lb.
• EZ curl bar: often 7 to 10 kg or 15 to 25 lb. Weigh yours.
• Trap bar: usually 20 to 30 kg or 45 to 65 lb.
• Smith machine: varies a lot, and some are counterbalanced. Check the label.

Loading tips

• Heaviest plates go on first, closest to the collar.
• Load both sides before lifting. Always use collars on heavy sets.
• Between sets, keep the plates that both weights share and only change the outside ones.
• Smaller plates (1.25 kg, 2.5 lb) make small jumps possible. They're the most useful plates you can buy.

When you can't make the weight

With a limited set of plates, some weights are impossible. Round down to the nearest weight you can make rather than up: a slightly lighter set is the safer miss. The plate calculator finds the nearest load either way.

Tip: Most commercial gyms have plenty of plates, but home gyms often don't. A few pairs of small plates make progression much smoother.

Never think about it again

Liftsmith only suggests weights your plates can make and draws the bar with the plates on each side for every set. During rest it shows the next set's plates and what to change ("take off 2.5, then add 5 each side"), so you can load while you rest.