Many people wish to approximate their strength level through certain exercises. These exercises include the OG bench press, squat, and so on and so forth. Fitness experts over the years have created an assortment of tables (typically using a ratio of the weight to their own body weight) to estimate relative strength tables. From my experience over the years training around 50ish people here are my standards (modeled off this site's tables).
BENCH PRESS
Beginner: 45 - 75% of BW
Novice: 75 - 115% of BW
Intermediate: 115 - 140% of BW
Advanced: 140 - 170% of BW
Elite: over 170% of BW
SQUAT
Beginner: 65 - 105% of BW
Novice: 105 - 150% of BW
Intermediate: 150 - 185% of BW
Advanced: 185 - 215% of BW
Elite: over 215% of BW
DEADLIFT
Beginner: 85 - 130% of BW
Novice: 130 - 170% of BW
Intermediate: 170 - 205% of BW
Advanced: 205 - 240% of BW
Elite: over 240% of BW
If you wish to compare other exercises check that link out above, but I really only see these 3 being necessary to measure strength levels.