One Rep Max Calculator
- Epley: 1RM = weight × (1 + reps/30)
- Brzycki: 1RM = weight × (36 / (37 − reps))
- Lombardi: 1RM = weight × reps^0.10
- Mayhew: 1RM = (100 × weight) / (52.2 + 41.9 × e^(−0.055 × reps))
Knowing your One Rep Max (1RM) is essential for building strength, planning workouts, and tracking progress. Our One Rep Max Calculator uses proven formulas to estimate the maximum weight you can lift for one perfect repetition in exercises like bench press, squat, deadlift, overhead press, and more.
Whether you’re looking for a 1RM calculator, a one rep max calculator for squat, or a bench press one max rep calculator, this tool gives you accurate results instantly.
Training Zones Based on Your 1RM
| Goal | % of 1RM | Notes |
|---|---|---|
| Power | 85–95% | Low reps, explosive speed |
| Strength | 80–90% | Heavy weight, long rest |
| Hypertrophy (Muscle Growth) | 65–80% | Moderate weight, moderate reps |
| Endurance | 40–65% | Higher reps, shorter rest |
| Technique Work | 30–50% | Perfect for beginners & warm-ups |
What Is One Rep Max (1RM)?
Your One Rep Max is the maximum amount of weight you can lift one time with correct form.
It is the gold standard for:
- Measuring strength levels
- Designing weightlifting programs
- Estimating training zones
- Tracking progress over time
Instead of testing 1RM directly (which can be risky), this 1rm max calculator safely estimates your maximum strength using lighter weights.
How to Calculate 1RM (One Rep Max)?
Most athletes and trainers estimate 1RM using proven scientific formulas.
The 1RM calculation uses:
Formula (Epley Formula – Most Accurate for Strength Training)
Example:
If you lifted 80 kg for 6 reps, then:
Your estimated one rep max is 96 kg.
Our 1RM calculator does this automatically using three scientific methods (Epley, Brzycki, Lombardi) and gives the most accurate estimate.
Why Use a One Rep Max Calculator?
✔ Train in the correct intensity zones
(60%, 70%, 85% — depending on your goal)
✔ Build strength safely
No need to attempt dangerous max lifts.
✔ Track strength improvements
✔ Perfect for squat, bench press, and deadlift programs
1RM Strength Percentage Chart
Use this chart to plan workouts at different intensities.
| Training Goal | % of 1RM | Reps |
|---|---|---|
| Max Strength | 85–100% | 1–5 |
| Hypertrophy | 65–85% | 6–12 |
| Endurance | 40–65% | 12–25 |
Our one rep max calculator squat also show these percentages automatically.
1RM Examples for Different Exercises
1RM Bench Press Example
You lift 60 kg for 8 reps:
→ Estimated bench press one rep max = 75–78 kg
1RM Squat Example
You squat 100 kg for 5 reps:
→ Estimated squat 1RM = 115–118 kg
1RM Deadlift Example
You deadlift 140 kg for 3 reps:
→ Estimated 1RM = 150–155 kg
These examples appear dynamically inside your tool results.
How Accurate Is a One Max Rep Calculator?
A one max rep calculator is typically 90–95% accurate when:
✔ You use strict form
✔ You use a weight heavy enough (3–10 reps)
✔ You avoid failure reps
The tool becomes less accurate if:
✘ Reps are extremely high
✘ You guess reps instead of completing them
✘ Your form breaks
For best results, input a weight you lifted for 3 to 8 reps with solid form.
Benefits of Knowing Your 1RM
Knowing your 1RM helps you:
- Set proper training percentages
- Create strength cycles
- Avoid overtraining
- Measure strength objectively
- Build muscle efficiently
This is why every serious lifter uses a 1RM calculator instead of guessing.
Advanced: Different 1RM Formulas Used
Our One Rep Max Calculator uses multiple science-backed formulas:
Epley
Best for compound lifts
Brzycki
Accurate for 2–10 reps
Lombardi
Best for experienced lifters
Your tool automatically averages the most reliable estimate.