Estimate your One-Rep Max in seconds

How the One Rep Max Calculator Works

This rpm calculator uses five proven formulas to estimate your one-rep max (1RM) quickly and clearly.

uses five proven strength formulas to give you an accurate one-rep max (1RM) prediction. Each equation—Epley, Brzycki, Lombardi, Mayhew, and O’Conner—was created by strength researchers to convert multi-rep performance into a single-rep equivalent. By averaging them, we minimize error and produce a reliable result for any athlete.

Your 1RM tells you how strong you really are. It’s the foundation for building workout percentages: powerlifters train around 85–95% for low-rep heavy work, while bodybuilders stay between 65–80% for muscle growth. Endurance training often uses 50–60% for high reps.

This calculator makes it easy: input the weight and reps you can perform, choose kilograms or pounds, and instantly see your predicted max along with a training table showing weights at 50–95% of that max.

Bench Press 1RM Calculator

The bench press 1RM measures your upper-body pushing strength. Enter your heaviest set of bench press reps, and the calculator will display your one-rep max in both kg and lb. Use the table to pick ideal training weights for chest and triceps growth.

Squat 1RM Calculator

Your squat 1RM is a key indicator of lower-body power. By tracking this number over time, you can balance strength between legs and upper body. Most athletes train at 70–85% for volume squats and 90%+ for testing maximal effort.

Deadlift 1RM Calculator

The deadlift 1RM shows total body strength. Because technique affects results, always use correct form and warm up well. Use this calculator after heavy sets of 3–6 reps for the most precise estimate.

Training Tip

Record your 1RM every 6–8 weeks to monitor progress. Combine this data with consistent nutrition, sleep, and recovery to see measurable improvements in strength and endurance.