What is your 1RM if you lift 140 kg for 3 reps?
If you can lift 140 kg for 3 repetitions, your estimated 1-Repetition Maximum (1RM) is 152 kg.
Formula Breakdown
There are multiple scientific formulas used by strength coaches to estimate a 1RM. Here is how they calculate your lift:
Epley Formula: 154 kg
The Epley formula is the industry standard and tends to be most accurate for low rep ranges (1-5). 140 × (1 + 3/30) = 154.0
Brzycki Formula: 148 kg
The Brzycki formula is often more conservative and reliable for higher rep sets (6-10). 140 × (36 / (37 - 3)) = 148.2
Lombardi Formula: 156 kg
The Lombardi formula uses an exponential model that does not assume a linear relationship, making it unique for power athletes. 140 × 3^0.10 = 156.3
O'Conner Formula: 151 kg
The O'Conner formula is a classic linear model widely used in weightlifting. 140 × (1 + 3/40) = 150.5
Wathan Formula: 153 kg
The Wathan formula uses a non-linear exponential decay curve to provide highly accurate estimation across a broad rep range. (100 × 140) / (48.8 + 53.8 × e^(-0.075 × 3)) = 152.6
Frequently Asked Questions
How do you determine your 1RM?
You can determine your 1 Rep Max (1RM) through direct testing or by using a 1 rep max calculator like this one. Direct testing involves working up to the heaviest single repetition you can perform safely. However, using submaximal sets (e.g., lifting 140 kg for 3 reps) and applying formulas like Epley or Brzycki is safer and highly accurate for most lifters.
Why is knowing your 1-repetition maximum important?
Knowing your 1-repetition maximum is crucial for creating structured training programs. Most powerlifting and strength routines use a percentage chart based off your 1RM to dictate how heavy your working sets should be. For example, lifting 75% of your 1RM for sets of 5 reps.
Can I use this for my bench press max calculator?
Yes! This calculator works perfectly as a bench max calculator, squat 1rm calculator, or deadlift calculator. The formulas remain the same regardless of the barbell lift. Simply input your weight and reps to generate your estimated one rep max and corresponding 1rm bench chart.
Calculate your working weights
Now that you know your 1RM is ~152 kg, use our RPE Calculator to figure out exactly what weights you should lift for your backoff sets.
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