Estimate your 1RM using 7 proven formulas. Compare your strength to population standards.
Use these percentages to program your training based on your estimated 1RM.
| % of 1RM | Weight | Reps | Training Goal |
|---|
Warmup ramp to your estimated 1RM. Adjust based on how you feel.
| Set | Weight | Reps | Purpose |
|---|
Your one rep max (1RM) is the maximum weight you can lift for a single repetition of a given exercise. Knowing your 1RM is essential for programming effective training -- most strength and hypertrophy programs prescribe weights as a percentage of your 1RM.
Rather than attempting a true 1RM (which carries injury risk), you can estimate it from a submaximal set. Simply enter the weight you lifted and the number of reps you completed, and this calculator will estimate your 1RM using seven well-established formulas.
This calculator uses seven peer-reviewed formulas to estimate your 1RM:
We display the average across all seven formulas as your primary estimate. For the most accurate result, use a weight you can lift for 3-8 reps. Accuracy decreases above 10 reps.
Enter your bodyweight and sex to see how your estimated 1RM compares to population-level strength standards. These standards are based on publicly available data from competitive powerlifting and gym populations, categorized into five levels:
This calculator estimates your one rep max (1RM) -- the heaviest weight you can lift for a single repetition on a given exercise. Instead of risking injury by loading up a bar and grinding out a max attempt, you can enter a lighter weight and the number of reps you completed, and the tool will project your 1RM using seven peer-reviewed formulas. It also shows your strength level relative to other lifters and generates percentage-based training loads.
No single formula is perfect for every lifter. The Epley formula is the most widely used and works well across rep ranges. Brzycki is popular in academic research and tends to be very accurate for low-rep sets (1-7 reps). Wathan uses an exponential model that many consider the most accurate overall. This calculator averages all seven formulas to smooth out individual formula biases and give you a more reliable estimate.
Most serious strength and hypertrophy programs prescribe weights as a percentage of your 1RM. For example, a program might call for 5 sets of 5 at 80% of your 1RM. Without knowing your 1RM, you are guessing at the right weight. The training percentages table below your results translates your estimated max into specific weights for different rep ranges and training goals.
You do not need to test a true 1RM frequently. Instead, use this calculator every 4-8 weeks with a heavy set of 3-5 reps to track your progress. True max attempts are taxing on your nervous system and carry higher injury risk, so save them for competition or the end of a training cycle.
Each formula was developed from a different population of lifters and uses a different mathematical model (linear, exponential, or power). They tend to agree closely at low rep ranges and diverge more at higher reps. The average across all seven gives you the most balanced estimate.
The formulas work best for compound barbell lifts like the squat, bench press, deadlift, and overhead press. They are less accurate for isolation exercises, machine movements, or exercises where technique is a major limiting factor (like the Olympic lifts). The strength standards are only available for the five exercises listed in the dropdown.
The five levels (Beginner through Elite) represent where your estimated 1RM falls relative to the general lifting population at your bodyweight. An "Intermediate" rating means you are stronger than roughly half of all lifters. These standards are based on publicly available data from competitive powerlifting and gym populations.
More Free Tools