You maybe know that the light weight doesn’t`t help to build muscle. Also with heavy weight you be unable to perform correct sets and reps. So you really need to know how to choose the right weight for your workout. You can do it by finding weight, that challenges you when you do last reps of your exercise. But the more practical way is to figure out which weight you can put when you do 3-5 reps with a proper form of exercise.
You can use one-rep max calculator. Powerful tool which helps you to determinate a list of % of your 1-rep max. Besides you can you use the following chart to find out sets, reps, weight, based on your goal. It is better to use it for classic exercises like Bench press, Deadlift, Squat.
|MAXIMAL MUSCLE GROWTH (HYPERTROPHY)
|50-70 percent of your one-rep max
|75-85 percent of your one-rep max
|85-100 percent of your one-rep max
|One to three
|Three to five
|Four to six
|Six to 12
|One to five