Free tool
1-rep max calculator
Enter a set you have actually done. We estimate your one-rep max, show training loads by percentage and build a four-week beginner progression from it.
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Estimated 1RM
92 kg
high confidence
Epley
93
kg
Brzycki
90
kg
Sets of 1–5 reps predict a true max closely, so treat this as a working number.
Training loads
| Reps | % of max | Load (kg) |
|---|---|---|
| 1 | 100% | 92.5 |
| 3 | 92% | 85 |
| 5 | 86% | 80 |
| 8 | 78% | 72.5 |
| 10 | 74% | 67.5 |
| 12 | 70% | 65 |
Your 4-week beginner progression
Week 1 · Groove the pattern
60 kg
3 sets × 8 reps at 65% of estimated max
Week 2 · Add a set
62.5 kg
4 sets × 8 reps at 68% of estimated max
Week 3 · Add load, drop reps
67.5 kg
4 sets × 6 reps at 73% of estimated max
Week 4 · Test week
70 kg
3 sets × 5 reps, last set as heavy as stays clean at 77% of estimated max
- ›Estimated 1RM on the back squat: 92 kg. Train between 80 and 67.5 kg for the next four weeks.
- ›Leave two reps in reserve on every working set. Beginner strength comes from repeatable sessions, not from grinding singles.
- ›Add the smallest plate jump only when you finish every prescribed rep with clean technique two sessions in a row.
- ›Retest with a set of five in week four instead of a true single — same information, far less fatigue and risk.
1RM questions
How is one-rep max calculated?
We average the Epley (weight × [1 + reps/30]) and Brzycki (weight × 36/[37 − reps]) formulas. They disagree at high rep counts, and the blend tracks real lifts more closely for beginners.
How accurate is an estimated 1RM?
Very close from sets of 1–5 reps, roughly 5% high from 6–8 reps, and unreliable above 10 because endurance runs out before strength does. Retest with a set of five.
What percentage should a beginner train at?
60–70% of your estimated max for sets of 8, moving toward 75–80% for sets of 5 by week four, always leaving two clean reps in reserve.
Estimates only. Never test a true max alone or without a spotter, and stop any set that breaks technique.
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