Calculate your one repetition maximum (1RM) from any weight and rep count using five proven formulas: Epley, Brzycki, Lander, Lombardi, and O'Conner.
Enter your details and click Calculate to see results.
Saved Presets is a Supporter feature.
Tool History is a Supporter feature.
Tool Notes is a Supporter feature.
Choose kilograms (kg) or pounds (lbs).
Input the weight you lifted.
Input the number of repetitions completed (best accuracy for 2-10 reps).
See your estimated 1RM from all five formulas and the percentage training table.
The One Rep Max Calculator uses established formulas and methodologies to provide accurate, reliable results. Understanding how the calculation works helps you interpret your results correctly and make informed decisions based on the output. The calculator processes your inputs through validated mathematical models used by professionals in the field.
The One Rep Max calculation uses industry-standard formulas validated by experts in the field. These formulas account for all relevant variables and produce results consistent with professional tools and reference materials. Understanding the underlying formula helps you verify calculations manually when needed and gives you confidence in the results for important applications.
The One Rep Max calculation uses industry-standard formulas validated by experts in the field. These formulas account for all relevant variables and produce results consistent with professional tools and reference materials. Understanding the underlying formula helps you verify calculations manually when needed and gives you confidence in the results for important applications.
Percentage table from 100% to 50% of 1RM is an important aspect of this calculator that enhances its usefulness for a wide range of applications. This capability ensures that the tool meets professional standards and provides value across different use cases. Users who take advantage of this feature will find their workflow more efficient and their results more actionable.
Supports kg and lbs is an important aspect of this calculator that enhances its usefulness for a wide range of applications. This capability ensures that the tool meets professional standards and provides value across different use cases. Users who take advantage of this feature will find their workflow more efficient and their results more actionable.
Works for any lifting exercise is an important aspect of this calculator that enhances its usefulness for a wide range of applications. This capability ensures that the tool meets professional standards and provides value across different use cases. Users who take advantage of this feature will find their workflow more efficient and their results more actionable.
Interpreting your one rep max results requires context. A single number rarely tells the complete story. Consider your specific circumstances, goals, and any relevant benchmarks or reference ranges. Use these results as one data point among several when making decisions. For critical applications such as health decisions, consult with a relevant professional who can provide personalized guidance.
All formulas have similar accuracy within 2-5 reps range. Epley and Brzycki are most commonly used. Accuracy decreases for sets above 10 reps.
