W = bodyweight + added weight. The result shown is W minus your bodyweight.
Prefer a dedicated 1RM app? Try the StreetLifter 1RM calculator.
What is a one rep max (1RM)?
Your one rep max (1RM) is the most weight you can lift for one complete repetition of an exercise. It is the standard measure of maximal strength in powerlifting and streetlifting.
Testing a true max is tiring and carries some injury risk, so a calculator estimates it from a set you can complete, ideally 3 to 6 hard reps.
Which 1RM formula should you use?
Use the averaged Street Lifter option if you are unsure. For the bench press, Mayhew and Wathan are the best tested. For pull-ups and dips, Brzycki and Epley are reliable at 1 to 10 reps.
| Formula | Best for | Notes |
|---|---|---|
| Street Lifter | All lifts | Average of all formulas, the most balanced estimate |
| Brzycki | 1–10 reps | Simple and accurate for moderate rep ranges |
| Epley | General strength | The classic formula, used across strength sports |
| Lombardi | Higher reps | Gives higher estimates as reps go up |
| O'Conner | General | Like Epley with a smaller rep factor, slightly conservative |
| Wathan | Powerlifting | Exponential formula, good across wider rep ranges |
| Mayhew | Bench press | Developed and validated on the bench press |
| Muscle-up | Muscle-ups | Built for weighted muscle-ups |
How to get an accurate estimate
Use a set of 3 to 6 reps
Estimates are most accurate from a hard set of 3 to 6 reps. The more reps, the bigger the error.
Count your bodyweight on pull-ups and dips
Your bodyweight is most of the load on pull-ups, dips and muscle-ups. Enter your weight on the day, because a few kilos change the result.
Re-test under the same conditions
Use the same exercise, technique and formula every time, so the trend means something.
Common questions
How do I calculate my one rep max?
Pick the exercise, enter the weight you lifted and the reps you completed, and the calculator estimates your 1RM with formulas such as Epley and Brzycki. For pull-ups, dips and muscle-ups, also enter your bodyweight. The most accurate estimate comes from a hard set of 3 to 6 reps.
Can I calculate 1RM for bench press, squat and deadlift?
Yes. The calculator covers the bench press, squat and deadlift, plus weighted pull-ups, dips and muscle-ups. Each exercise has a recommended formula, for example Mayhew for the bench press.
What is the most accurate 1RM formula?
No single formula is best for everyone. Brzycki and Epley are accurate at 1 to 10 reps, Mayhew and Wathan suit the bench press, and the averaged Street Lifter option gives the most balanced estimate. Accuracy is highest with sets of 3 to 6 reps.
How do I calculate 1RM for weighted pull-ups?
Count your bodyweight as part of the load: add your bodyweight to the added weight, apply the formula, then subtract your bodyweight to get the added-weight 1RM. This calculator does that for you. For a pull-up-specific tool with training loads, use the weighted pull-up 1RM calculator.
Is this one rep max calculator free?
Yes. It is free, needs no sign-up and gives results instantly.
