SYSTEMM · CALCULATOR
./calculators/1rm
● 09 · TRAINING
One-rep max.
Enter a recent set, get an estimated 1RM by three formulas, with a confidence band and the percentage table for programming the next cycle.
● INPUTSRECENT SET
The set.
Formulas are most accurate at 1, 8 reps. Above 10 reps, the estimate is increasingly conservative. Below 3 reps, just attempt the lift.
● OUTPUTSESTIMATED 1RM
Your 1RM.
● AVERAGE OF 3 FORMULAS
263
LB
CONFIDENCE BAND 256, 270
Brzycki
253
Epley
263
Lombardi
272
● Percentage table for programming
%1RM
REPS RANGE
WEIGHT
USE FOR
95%
2, 3 reps
250
Peaking
90%
3, 4 reps
237
Strength
85%
5, 6 reps
224
Strength
80%
7, 8 reps
211
Strength / Hyp.
75%
9, 10 reps
198
Hypertrophy
70%
11, 12 reps
184
Hypertrophy
65%
13, 15 reps
171
Volume / Warm-up
60%
16, 20 reps
158
Endurance / Speed
● HOW THE THREE FORMULAS WORK
Brzycki: weight ÷ (1.0278, 0.0278 × reps). Most accurate at low rep counts. Epley: weight × (1 + reps ÷ 30). Mid-rep accurate, the most-used in commercial gyms. Lombardi: weight × reps0.10. More generous at higher rep counts. The average of the three is more reliable than any single formula, especially across rep ranges.
● PROGRAMMING NOTE
A safer way to use this: do not test 1RM monthly. Use the percentage table from a recent 3, 5 rep set to set training weights for the next cycle, and only attempt a true 1RM at the end of a peak block. The estimate replaces the test in 90% of training contexts.