Sports
One-Rep Max Training Zone Calculator
Estimate 1RM with Epley, Brzycki, and Lombardi equations, average them, calculate an intensity-zone load, and total planned work volume.
Epley estimated 1RM (kg)-
Brzycki estimated 1RM (kg)-
Lombardi estimated 1RM (kg)-
Three-formula consensus 1RM (kg)-
Raw target-intensity load (kg)-
Conservative loadable target (kg)-
Planned total repetitions-
Planned work-set volume (kg)-
Formula estimate spread (kg)-
Decision view
Three-formula 1RM range, intensity zones, and loadable barbell
Three-formula 1RM range, intensity zones, and loadable barbellFormula estimates form an uncertainty bracket while the selected percentage maps onto a conservatively loadable plate configuration.
Exact scenario comparisonCompleted repetitions changes while all other entered assumptions remain constant.
| Completed repetitions | Epley estimated 1RM (kg) | Brzycki estimated 1RM (kg) | Lombardi estimated 1RM (kg) | Three-formula consensus 1RM (kg) | Raw target-intensity load (kg) | Conservative loadable target (kg) | Planned total repetitions | Planned work-set volume (kg) | Formula estimate spread (kg) |
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How to use One-Rep Max Training Zone Calculator
- Enter a technically sound hard set of 1–15 repetitions.
- Select a percentage suitable for the training goal.
- Use the actual smallest loading increment available.
Calculator guide
Understanding One-Rep Max Training Zone Calculator
A repetition maximum is an estimate with formula uncertainty. This calculator keeps three common equations visible and rounds the training load down to available equipment.
Detailed calculation process
Detailed 1RM consensus and training-zone calculation
The default set is 100 kg for five reps, with an 80% target and 2.5 kg loading increments.
General formula: 1RM_E=w(1+r/30)1RM_B=36w/(37-r)1RM_L=w*r^0.11RM_C=(1RM_E+1RM_B+1RM_L)/3w_t=1RM_C*iw_load=floor(w_t/Δw)ΔwV=w_load*s*r_s Each equation maps the same set to a different estimate. The consensus is multiplied by intensity and rounded conservatively to a loadable value.
What each symbol means
Worked substitution with the default inputs
The default consensus 1RM is about 115.54 kg, producing a practical 90 kg target and 2,160 kg planned volume.
Worked situations
Practical examples
- The default 100 kg for five reps produces estimates from 112.5 to about 117.46 kg.
- The consensus is about 115.54 kg; 80% is 92.43 kg and rounds down to 90 kg with 2.5 kg increments.
Better inputs
Useful tips
- Prefer lower-repetition estimates for skilled compound lifts.
- Update from recent sets performed with consistent technique.
- Use velocity, RPE, and coaching context when available.
Before relying on the result
Limitations and common mistakes
- Equations estimate strength and do not measure a true maximal lift.
- Fatigue, exercise, sex, training age, tempo, range of motion, and proximity to failure alter accuracy.
- The planned volume is load×reps and does not measure physiological stress.
Reference
Key terms
- 1RM
- Maximum load estimated or achieved for one repetition.
- Intensity
- Training load as a percentage of 1RM.
- Volume load
- Load multiplied by completed repetitions.
Important note
Strength training carries injury risk. Use competent supervision, safe equipment, spotters or safeties, appropriate progression, and medical guidance when needed.
Frequently asked questions
Why cap repetitions at 15?
Rep-based 1RM formulas become less reliable as repetition count rises.
Why round down?
It avoids prescribing above the selected intensity when the exact load cannot be assembled.
Can I use this for every exercise?
Accuracy varies substantially by exercise and athlete.