Free One Rep Max Calculator - Estimate Your 1RM
Calculate your one rep max from submaximal lifts using Brzycki, Epley, and other formulas. Plan your strength training.
Quick Answer
One Rep Max is the maximum weight you can lift once. Estimated from lighter sets: 1RM = Weight × (1 + Reps/30) (Epley). Example: 200 lbs × 5 reps = 233 lb estimated 1RM.
Key Facts about One Rep Max Calculator:
- 1RM = maximum single repetition weight
- Multiple estimation formulas exist
- Most accurate with 1-10 reps
- Use for training percentages
- Safer than testing actual 1RM
- Formulas less accurate above 10 reps
Why Use Our One Rep Max Calculator?
1RM calculation:
1RM Estimator
Calculate max from any rep range.
Multiple Formulas
Brzycki, Epley, Lander.
Percentage Chart
Training percentages.
Strength Standards
Compare to benchmarks.
Instant Results
Get estimate immediately.
Private
Your data stays secure.
How to One Rep Max Calculator in 3 Easy Steps
Estimate 1RM:
Enter Weight
Weight lifted.
Enter Reps
Repetitions completed.
View 1RM
See estimated maximum.
Why Use Our Calculator?
Safe estimation
Multiple formulas
Training percentages
Track progress
Common Use Cases for One Rep Max Calculator
Perfect for:
Frequently Asked Questions
Everything you need to know about our one rep max calculator
How accurate is 1RM calculator?
Within ±5% for 1-5 reps. Less accurate above 10 reps.
Most accurate with 1-5 reps (±5%). Accuracy decreases with higher reps. Different exercises may need different formulas.
Should I test my actual 1RM?
Estimating from 3-5 rep max is safer. Only test actual with spotters.
Testing actual 1RM carries injury risk. Estimation from 3-5 rep max is safer and nearly as accurate. Only test with proper spotters and technique.
Still have questions? Try the tool yourself!
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