One Rep Max Calculator
Calculate your one-rep max (1RM) for bench press, squat, and deadlift using standard formulas like Brzycki and Epley.
Complete Guide: One Rep Max Calculator
Everything you need to know about using this tool effectively
This calculator estimates your one-rep max (1RM) based on the weight you lifted and the number of repetitions you completed. It uses the Epley formula, which multiplies the weight by one plus reps divided by 30, to predict the maximum load you can lift for a single repetition without testing it directly.
A strength training tool that predicts your maximum lift capacity from submaximal sets. Rather than risking injury by testing your true one-rep max, you can enter any recent working set and the calculator extrapolates your estimated 1RM. This value is useful for programming training percentages and tracking strength gains over time.
Strength Program Planning
Use your estimated 1RM to calculate the correct weights for percentage-based training programs like 5/3/1 or Texas Method.
Progressive Overload Tracking
Estimate your 1RM after each training cycle to verify strength gains and adjust working weights accordingly.
Competition Preparation
Plan your openers and attempt selections for powerlifting or weightlifting meets based on recent training data.
Safe Strength Testing
Avoid the injury risk of a true max attempt by estimating your 1RM from a moderate-rep set instead.
Enter the Weight Lifted
Type the amount of weight you used for your most recent working set in pounds or kilograms.
Enter Reps Completed
Input how many repetitions you completed with that weight. The formula is most accurate between 1 and 12 reps.
View Your Estimated 1RM
The calculator displays your estimated one-rep max along with recommended weights for common rep ranges.
Use a set where you had 1 to 3 reps left in the tank for the most accurate estimate.
The Epley formula is less accurate above 12 reps, so stick to sets of 12 or fewer for reliable predictions.
Recalculate your 1RM every 4 to 6 weeks to keep your training percentages aligned with your current strength level.
Different muscle groups may have different rep efficiency, so estimate 1RM separately for each major lift.
Use wrist wraps or a belt for your heaviest test sets but not for regular training sets you use for estimation.
What is a one-rep max?
A one-rep max is the heaviest weight you can lift for a single repetition with proper form. It is the standard measure of absolute strength in powerlifting and weightlifting and is used to set training loads as percentages of your maximum capacity.
How accurate is the Epley formula?
The Epley formula is reasonably accurate for sets between 1 and 12 reps, typically within 5 to 10 percent of the true 1RM. Accuracy decreases with higher rep sets because muscular endurance becomes a larger factor beyond 12 reps.
Should I ever test my true 1RM?
Testing a true 1RM carries injury risk and is not necessary for most lifters. Estimated 1RM from submaximal sets provides a safe and practical alternative for programming. Competitive lifters may test periodically under supervision.
What are training percentages?
Training percentages are loads expressed as a fraction of your 1RM. For example, 85 percent of 1RM is typically used for sets of 3 to 5 reps in strength-focused programs. These percentages help coaches prescribe appropriate intensities for different training goals.
Can I use this for Olympic lifts?
Yes, you can estimate 1RM for the snatch, clean and jerk, and their variations. Keep in mind that Olympic lifts have a larger skill component than powerlifts, so estimated values may be less precise.