Calculate your estimated 1RM from reps
Your one-repetition maximum (1RM) is the greatest load you can lift once for a specific exercise with acceptable technique. ATHLOMETRY estimates it from the load and repetitions you complete, so you can get a practical strength reference without attempting a true maximum every time.
EpleyOne commonly used prediction equation
BrzyckiA second estimate for comparison
40–100%Automatic training-load table
1RM formulas used
Epley: 1RM = load × (1 + reps / 30)
Brzycki: 1RM = load × 36 / (37 − reps)
Brzycki: 1RM = load × 36 / (37 − reps)
The two equations will not always return exactly the same number. ATHLOMETRY displays both values and currently uses their average for the percentage-load table, giving you a simple working estimate rather than hiding the variation between formulas.
How to get a more useful estimate
- Use a set performed with consistent technique and full range of motion.
- Lower-repetition sets generally provide a better strength estimate than very high-repetition sets.
- Do not compare 1RM values from different exercises as if they measured the same quality.
- Repeat testing under similar conditions when monitoring progress.
Research comparing repetition-based prediction equations shows that accuracy depends on the exercise, population and number of repetitions. Studies commonly recommend keeping prediction sets relatively short; error tends to increase as repetitions rise.
How to use the percentage table
The load table converts the estimated 1RM into practical kilogram targets. Treat these as starting points rather than mandatory prescriptions: repetitions in reserve, velocity, exercise selection, training age and fatigue all influence the load that is appropriate on a given day.
Is an estimated 1RM the same as a tested 1RM?
No. It is a prediction from a submaximal set. A direct 1RM test measures the heaviest successful single under the test conditions.
How many repetitions should I use?
Shorter sets are usually preferable. Prediction accuracy commonly decreases as the number of repetitions increases, so sets around 10 repetitions or fewer are a sensible practical choice.
Why do Epley and Brzycki give different results?
They model the relationship between repetitions and maximal strength differently. Showing both gives you a better sense of the uncertainty in any prediction equation.
Can I use this for squat, bench press and deadlift?
Yes as a practical estimate, but prediction error can differ between exercises and individuals. Track each exercise separately.