Epley Brzycki Comparison
Compare Epley and Brzycki one-rep-max estimates from load and repetitions.
Description
Epley and Brzycki equations estimate one-repetition maximum from a lifted load and repetition count.
Epley and Brzycki equations estimate one-repetition maximum from a lifted load and repetition count. Their disagreement grows with different model behavior.1
Compare Epley and Brzycki one-rep-max estimates from load and repetitions.
When to use Epley Brzycki Comparison
Use this tool to compare Epley and Brzycki one-rep-max estimates from load and repetitions.
Prepare the measured movement, timing, load or preassigned score requested. Keep protocols, units, paired measurements and caller-selected thresholds consistent.
How to use Epley Brzycki Comparison and understand its results
- Prepare the measured movement, timing, load or preassigned score requested. Keep protocols, units, paired measurements and caller-selected thresholds consistent.
- Enter liftKg, repetitions using the field table and calculation rules, then run the tool.
- Read epleyOneRepMaxKg, brzyckiOneRepMaxKg, differenceKg. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| liftKg | Lift kg | number | Required |
| repetitions | Repetitions | number | Required |
Enter positive kg and safe integer repetitions 1–36. Return both estimates and Epley-minus-Brzycki kg.
Epley=load(1+reps/30), except reps=1→load; Brzycki=36load/(37−reps) Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| epleyOneRepMaxKg | Epley one rep max kg | number |
| brzyckiOneRepMaxKg | Brzycki one rep max kg | number |
| differenceKg | Difference kg | number |
{
"input": {
"liftKg": 100,
"repetitions": 5
},
"output": {
"epleyOneRepMaxKg": 116.66666666666667,
"brzyckiOneRepMaxKg": 112.5,
"differenceKg": 4.166666666666671
}
}Limitations and assumptions
Accepted high repetition counts do not establish model accuracy. No effort-to-failure check, uncertainty or training prescription is supplied.
Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use One Rep Max Training Loads: Generate lift training loads from a measured one-rep max and chosen fractions. For a complementary task, use RPE Reps In Reserve: Convert a strength-set RPE rating to estimated reps in reserve on a chosen scale.
References
-
Epley Brzycki Comparison — tool.io
Similar or alternative tools
- One Rep Max Training Loads
Generate lift training loads from a measured one-rep max and chosen fractions.
- RPE Reps In Reserve
Convert a strength-set RPE rating to estimated reps in reserve on a chosen scale.