Here’s how you figure out what weight dumbbells you should buy.

Beginners – Consider a 5-50lb dumbbell set. You can make use of the 5lb dumbbells for things like reverse flys or lateral raises where your muscles are not built up enough to lift the kind of heavier weight that you do while bench pressing. And if 50lb dumbbells seem like more than you’ll be lifting, you might be surprised how quickly you will work up to them for max attempts, and even go beyond.

Intermediate Lifters – If you’ve already been lifting a bit and expect to do it a lot more, 50lb dumbbells are not going to be enough for you. A 5-75lb or even a 5-100lb set might be good. You might not need the smaller sizes like 5lb, but again, the additional cost of them is so little it may not matter much.

When deciding what weight dumbbells you should buy, consider also the type of dumbbells, because they come in a few main types:

  1. Fixed Weight Dumbbells – These can be any dumbbells that come in all kinds of sizes from 1lb to 100lb and sometimes higher. They aren’t adjustable. They are just solid dumbbells. The handles are steel, and the heads are iron, with either a paint or rubber or urethane coating.
  2. Adjustable Dumbbell Handles – This is the economy version of adjustable dumbbells. Get standard handles with plates, or olympic handles with plates (standard and olympic aren’t compatible), and you can load them up to at least 80lbs, depending on which ones you get. Be sure to get 10lb and smaller plates, or they are too unwieldy. This is cost effective, replacing a whole set up fixed dumbbells that take up more space. You’ll probably want a weight tree to store all your plates.
  3. Adjustable Dumbbells – Here are more handy adjustable dumbbells that don’t require you to buy bunch of plates. They’re a little more expensive but have an adjustment mechanism so you don’t have to worry about storing all the weight plates or having to spend all that extra time changing weights. These are made to be quick and store in a small space.