Methodology

Our Methodology

This page explains how the site estimates one-rep maxes, assigns strength levels, and generates training recommendations on a static frontend.

1RM formulas

The calculator compares three classic one-rep max formulas. Epley is used as the general default because it performs well for many lifters in low-to-moderate rep ranges. Brzycki tends to be slightly more conservative when reps climb. Lander provides a useful middle line between the two.

  • Epley: 1RM = Weight × (1 + Reps/30)
  • Brzycki: 1RM = Weight × (36 / (37 - Reps))
  • Lander: 1RM = (100 × Weight) / (101.3 - 2.67123 × Reps)

Strength standards model

The strength standards calculator uses bodyweight-adjusted ratio thresholds for each core lift and sex category. Those thresholds are modeled to reflect practical beginner, novice, intermediate, advanced, and elite bands for general lifting populations rather than official meet qualification rules.

The percentile output is derived from the user’s position within the current band rather than from a live external dataset. It is intended as a stable benchmark indicator for a static site.

Why some outputs are modeled instead of live

Some parts of the site, such as percentiles and standards bands, are intentionally modeled rather than connected to a live third-party feed. That design choice keeps the pages fast, reproducible, and transparent. A static front-end calculator should not imply that every ranking or percentile is being pulled in real time from a global dataset if that is not actually happening.

Instead, the site uses explicit threshold bands, ratio ladders, and fixed percentile curves so the user can understand what the output means. The tradeoff is that the percentile is a planning aid, not an official live ranking. That tradeoff is acceptable as long as the page says so clearly, which is why many of the tool pages include direct disclosure when a value is modeled.

Rounding, units, and practical output

Training outputs are designed to be usable on real gym equipment, not just mathematically neat. That means the site often rounds loads to practical increments such as 2.5 kg or 5 lb when generating working weights or plate plans. Formula outputs may still show more precise values, but planning outputs generally favor what can actually be loaded.

Unit conversion follows the same principle. The site supports both kilograms and pounds, but the goal is not to pretend that every converted number remains equally meaningful after rounding. In practice, planning tools should prioritize clarity over false precision.

Limits of the models

No calculator on this site should be treated as a substitute for coaching judgment, meet-day officiating, or medical advice. Rep-max equations are estimates. Standards bands are simplified comparisons. Relative-strength formulas such as Wilks or DOTS are useful, but they are still abstractions layered on top of real performance. Even a well-built calculator compresses technique, recovery, training age, body composition, and federation-specific rules into a simpler number.

The methodology page exists to make those limits explicit. A strength site is more trustworthy when it explains not only what it calculates, but also what it does not claim to know. That is why this site favors plain formulas, stated assumptions, and user-facing disclosures over inflated promises of perfect accuracy.

References

  • Epley, B. (1985). Poundage Chart. Boyd Epley Workout.
  • Brzycki, M. (1993). Strength Testing. JOPERD, 64(1), 88-90.
  • Lander, J. (1985). Maximums Based on Reps. NSCA Journal.

Additional pages on the site may reference practical powerlifting scoring systems, widely used barbell conventions, and public federation rules or terminology. When those pages use modeled assumptions rather than a live external database, the model should be described in the page copy itself.