1RM Calculator
Calculate your Pec Deck one rep max
Enter weight and reps to see your estimated 1RM
Based on 80kg(M)/60kg(F) BW
| Beg | Int | Adv | |
|---|---|---|---|
| Male | 25 kg | 50 kg | 80 kg |
| Female | 12 kg | 24 kg | 40 kg |
5×8 @ 37.5 kg, BW 70kg
1RM = 50 kg (male int.)
| Reps | % | Weight |
|---|---|---|
| 1 | 97% | 48.5 kg |
| 3 | 91% | 45.5 kg |
| 5 | 86% | 43 kg |
| 8 | 79% | 39.5 kg |
| 10 | 75% | 37.5 kg |
| 12 | 71% | 35.5 kg |
| 15 | 67% | 33.5 kg |
Male, 80kg BW
Compared with exercises targeting the same muscle group.
| Exercise | Equipment | Muscles | MET | Int. 1RM |
|---|---|---|---|---|
Pec Deck | Machine | Chest | 3.5 | 50 kg |
| Barbell | Chest | 6.5 | 80 kg | |
| Barbell | Chest, Shoulders | 6.5 | 65 kg | |
| Barbell | Chest | 5.5 | 85 kg |
1RM (one rep max) is the maximum weight you can lift for a single repetition of a given exercise. It is a standard measure of muscular strength used by coaches, athletes, and researchers worldwide.
This calculator uses the Epley formula: 1RM = Weight × (1 + Reps ÷ 30). It provides a reliable estimate when lifting in the 2-12 rep range.
Strength standards are reference values based on data from competitive and recreational lifters. Standards are based on 80 kg (male) and 60 kg (female) reference body weights.
Log weight, reps & sets. Auto-estimate 1RM and calories. Completely free, no ads.
GymGrid automatically estimates your 1RM from your training data
Quick to log between sets. Seeing my last session instantly means no more guessing what weight to use.
Free with all these features? Switched from a subscription app and haven't looked back.
Love the simple UI. No clutter, just tracking. Exactly what I needed.
