How to calculate your bench press 1RM
A predicted one-repetition maximum (1RM) uses a completed submaximal set to estimate the load you might lift for one repetition. It is a mathematical estimate, not a direct test.
Step 1: Record a completed set
Use the weight you actually lifted and the number of repetitions you completed. Keep the unit consistent.
Step 2: Apply a prediction equation
Common equations include Epley, Brzycki, Lander, Lombardi and O’Conner. For example, Epley is:
Step 3: Compare equations
Different equations can produce different results. Our calculator displays all five and uses their arithmetic mean as a representative estimate rather than hiding the spread.
Worked example
If a lifter completes 185 lb for 5 repetitions, Epley gives 215.8 lb. Other equations give slightly different estimates. That difference is a reminder that the result is a model-based estimate.
Limits
Technique, fatigue, range of motion, equipment and individual muscular endurance can change the relationship between repetitions and 1RM. The estimate should therefore be interpreted as a reference rather than a guaranteed maximum.