The set matters
A lower-repetition set and a clear RIR estimate usually provide a more useful basis.
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One-Rep Max and Training Load Calculator
Estimate your one-rep max, compare formulas, and turn the result into a practical training load.
You do not need to test your actual 1RM. Use a controlled set and treat
the result as a reference for planning loads.
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How to interpret the result
The calculated 1RM is a decision-making reference, not an exact measurement or a guaranteed load.
The range shows the difference
Epley and Brzycki do not always agree. The displayed range is not a statistical confidence interval.
The practical load is usable
We round the mathematical load to your available increment and show a lower alternative when appropriate.
Methodology and safety
The tool combines two established equations and explains their limits to avoid false precision.
Formulas used
Epley: weight × (1 + effective repetitions / 30).
Brzycki: weight × 36 / (37 - effective repetitions).
If you know your RIR and it is between 0 and 2, it is added to the completed repetitions to better represent the set's capacity.
Train with context
Prioritize controlled technique, a proper warm-up, gradual progression, and supervision when the exercise requires it. Fatigue, exercise selection, range of motion, and experience can change the result.
Frequently asked questions
What is a one-rep max (1RM)?
It is the heaviest load a person can lift once in a specific exercise. This tool estimates it from a submaximal set.
Do I need to test my actual 1RM?
No. You can use a multi-repetition set to obtain a useful estimate without attempting a maximal load.
Which formula is better, Epley or Brzycki?
Neither is exact for every person and exercise. That is why we show both, highlight one as the primary estimate, and make the difference visible.
What does RIR mean?
RIR means repetitions in reserve: the number of additional repetitions you believe you could have completed with acceptable technique.
Why does the estimate change with high-repetition sets?
The formulas can diverge more, and muscular endurance has a greater influence when a set contains many repetitions.
What weight should I use for 8 or 10 repetitions?
The planner estimates a mathematical load and rounds it to your available increment. It is a reference, not a guarantee that you will complete those repetitions.
Why is the practical load different from the exact load?
The exact load may not be possible with your plates, dumbbells, or machine. The practical load is rounded to the increment you enter.
Is my 1RM the same for every exercise?
No. Technique, range of motion, equipment, fatigue, and experience affect the result. Calculate each exercise separately.