What is an estimated 1RM?
A one-rep max is the greatest load lifted once with the required technique. An estimated 1RM infers that capacity from a lighter set, avoiding the need to directly test a maximal attempt.
The Epley equation
For two to ten repetitions, the tool multiplies load by one plus repetitions divided by 30. A single completed repetition is returned as the entered load rather than inflated by the equation. The formula is most relevant to a challenging, technically consistent set.
How to use this calculator
- 1Enter the total load lifted, including the bar when applicable.
- 2Enter completed repetitions from 1 to 10.
- 3Calculate the estimate and treat percentage loads as approximate planning references.
Understanding your result
Different lifts and individuals have different repetition-to-load relationships. A set stopped far from fatigue can underestimate capacity. Avoid attempting the displayed maximum solely because a formula produced it; technique and appropriate supervision still matter.
Assumptions & limitations
- The estimate does not account for fatigue, tempo, range of motion, equipment, or repetitions left in reserve.
- Machine, dumbbell, and barbell loads are not interchangeable measures of strength.
Frequently asked questions
Why is the calculator limited to 10 reps?+
Higher-repetition sets are more influenced by muscular endurance and generally make maximum-strength predictions less useful. The cap keeps the tool within a more practical range.
Do I include the bar's weight?+
Yes, enter total external load for a barbell lift. Use the same convention each time so comparisons remain meaningful.
Does one rep mean my true maximum?+
Only if that rep was actually a maximal successful effort. The calculator returns a one-rep entry unchanged; it cannot tell whether you could lift more.
Can I compare my squat estimate with my deadlift estimate?+
They describe different lifts. Track each lift under consistent technique and equipment rather than assuming one estimate predicts another.
