One Rep Max — Brzycki Formula
Calculate your 1RM using the Brzycki formula, known for accuracy in the 2–10 rep range.
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How the One Rep Max — Brzycki Formula Works
The One Rep Max — Brzycki Formula uses one or more validated strength formulas — Epley, Brzycki, Lombardi, or others — to estimate a strength benchmark from your input data. These equations were developed from large datasets of competitive and recreational lifters and are standard in strength and conditioning programming.
Use the result to set percentage-based training weights across your program. Most strength programs prescribe work at 60–85% of your estimated maximum, building volume and intensity progressively.
Frequently Asked Questions
How is the calculation performed?
This calculator uses one or more of the established strength formulas — including Epley, Brzycki, and others — which were developed from large datasets of powerlifters and strength athletes. Each formula produces slightly different estimates, and the calculator typically shows the most conservative or averaged result.
Is it safe to attempt my estimated maximum?
Maximum lifts carry inherent injury risk and should only be attempted with proper warm-up, technique, an experienced spotter, and appropriate equipment. The estimated value is primarily used for programming — setting training percentages — rather than as a goal to test directly.
How does my bodyweight affect these numbers?
Bodyweight is a key factor in relative strength metrics. Heavier lifters tend to move more absolute weight, while lighter lifters often have higher strength-to-weight ratios. Bodyweight-adjusted metrics like Wilks, IPF Points, and DOTS allow fair comparison across weight classes.
How do I use this to program my training?
Most strength programs use percentages of your estimated maximum (e.g., 70%, 80%, 85%) to prescribe working weights across different rep ranges. Programs like 5/3/1, Texas Method, and others are built around this percentage-based approach.
How often should I recalculate?
Recalculate every 4–8 weeks as your strength progresses. Consistent progressive overload will improve your training max over time. Many lifters also use in-session performance (rep PR attempts at sub-max weights) to update estimates without attempting true maximums.