Two-formula average
Computes Epley and Brzycki and shows the average.
Fitness Calculator
1RM Calculator — Estimate Your One-Rep Max
Enter the weight lifted and reps to estimate your one-rep max with the Epley and Brzycki formulas, plus a training-percentage table.
Estimated 1RM (Average)
91.7
Epley 93.3 · Brzycki 90
Training percentages
100% · 1 ≈ reps91.7
95% · 2 ≈ reps87.1
90% · 4 ≈ reps82.5
85% · 6 ≈ reps77.9
80% · 8 ≈ reps73.3
75% · 10 ≈ reps68.8
70% · 12 ≈ reps64.2
60% · 16 ≈ reps55
What is the 1RM calculator?
Your one-rep max (1RM) is the most weight you can lift for a single rep. Testing a true max is risky, so it's safer to estimate it from a lighter set (weight × reps). This tool uses the two most common formulas — Epley and Brzycki — and shows the average plus a training-percentage table.
How to use
- 1 Enter the weight you just lifted.
- 2 Enter the reps you completed (1–20).
- 3 Read your estimated 1RM and target weights by percentage.
Highlights
Percentage table
Weights and approximate reps from 60% to 100%.
Unit-agnostic
Works in kg or lb — results match your input unit.
FAQ
Epley or Brzycki — which is right?+
Both are widely used. They agree at low reps (≤5) and diverge as reps rise, so the average is a sensible default.
How many reps stay accurate?+
Accuracy is best in the 1–10 rep range; error grows as reps increase.
Should I test a true 1RM?+
Not necessarily — estimation is recommended to avoid injury. If you do test, always use a spotter and safeties.
Related tools
Estimates only; your true 1RM varies with condition, lift, and technique. Attempt maxes with a spotter and safeties, and don't push through pain.