Wilks Score: How to Compare Strength Across Body Weights

Imagine two powerlifters. The first competes at 74kg and totals 600kg (squat + bench + deadlift). The second competes at 105kg and totals 700kg. Who is stronger, relative to their body weight?

Simply dividing total by body weight doesn't answer this correctly. Heavier lifters carry more absolute muscle mass, which scales faster than body weight — so a naive ratio systematically undervalues heavier competitors. The Wilks coefficient was developed specifically to solve this problem.

The Problem With Simple Ratios

The most intuitive way to compare lifters is the strength-to-weight ratio: total divided by body weight. A 74kg lifter totalling 600kg lifts 8.1× bodyweight. A 105kg lifter totalling 700kg lifts 6.7× bodyweight. By this measure, the lighter lifter wins by a wide margin.

But this overpenalises heavier lifters. The relationship between body mass and maximal strength is not linear — it follows a power law. Muscle cross-sectional area, which determines force production, scales with the square of linear dimensions, while body weight scales with the cube. This means a lifter twice as heavy as another will typically be able to lift considerably more than twice the weight, even if neither has a structural advantage.

Sports science has long grappled with this. The Sinclair coefficient (used in Olympic weightlifting) and the Schwartz/Malone formula (an earlier powerlifting attempt) both tried to address it, with varying success. Robert Wilks, then an Australian Powerlifting Federation official, developed his coefficient in the 1990s using competition data to produce coefficients that fit actual performance distributions across weight classes.

How the Wilks Formula Works

The Wilks coefficient is calculated using a 5th-degree polynomial function of body weight. The formula is:

Wilks Score = Total × (500 / (a + b·w + c·w² + d·w³ + e·w⁴ + f·w⁵))

Where w is body weight in kilograms and a through f are sex-specific constants derived from regression on competition data. The denominator estimates the "expected" total for an elite lifter at that body weight, so dividing your actual total by it — then multiplying by 500 to keep the output in a meaningful range — gives your Wilks score.

A Wilks score of 500 represents an approximate world-class standard. Most well-trained recreational lifters score in the 300–400 range. The polynomial shape of the formula means it adjusts for the known non-linearity of the strength-to-weight relationship across the full range of competitive body weights (roughly 52–145kg).

Wilks Scores in Context

Wilks Score	Approximate Level
< 200	Beginner
200–300	Intermediate recreational lifter
300–400	Competitive recreational / regional level
400–500	Serious competitor / national-level potential
500–600	National / international elite
> 600	World-class

These benchmarks are approximate and vary by federation and era. Raw (no equipment) totals yield lower Wilks scores than equipped totals, and masters-category lifters naturally score lower than open-category competitors at their peak.

The 2020 Update: IPF GL Points

In 2019, the International Powerlifting Federation (IPF) — the sport's largest and most prestigious federation — replaced the Wilks formula with a new system called IPF GL Points (Good Lift Points). The motivation was that the original Wilks data was derived from equipped powerlifting records from the 1990s, which may not accurately reflect the raw lifting that dominates modern competition.

The IPF GL formula uses updated regression coefficients based on current world records, separately for raw and equipped lifting. It also uses a slightly different mathematical form. In practice, IPF GL and Wilks rankings are highly correlated — they rarely disagree on who is the strongest lifter in a meet — but the IPF's official use of GL Points means Wilks is now considered the "old" system by many competitive powerlifters.

Despite this, Wilks remains the most widely recognised strength metric outside of IPF competition. Coaches, online communities, and non-IPF federations continue to use it as a de facto standard for cross-weight comparison. If someone cites a "Wilks score" without further context, they almost certainly mean the original Robert Wilks formula, not IPF GL.

Using Wilks for Your Own Training

Even outside competition, the Wilks score is a useful training metric. It lets you:

• Track progress fairly as body weight changes: If you gain 5kg and your total increases by 30kg, your Wilks score tells you whether that was meaningful strength gain or just a consequence of being heavier.
• Compare yourself to others: Online lifting databases (OpenPowerlifting.org) display Wilks scores for every recorded competition result, making it easy to benchmark your training totals against real competitive standards.
• Set goals grounded in realistic standards: Aiming for a Wilks of 350 is a clearer goal than "I want to total 500kg," because it adjusts automatically for your body weight class.

Sources

1. Wilks, R. (1990s). Wilks Coefficient formula. International Powerlifting Federation (original coefficient derivation; unpublished technical document).
2. International Powerlifting Federation. (2019). IPF GL Points system. IPF Technical Rules. Retrieved from ipf.com.
3. Cleather, D.J. (2006). Adjusting powerlifting performances for differences in body mass. Journal of Strength and Conditioning Research, 20(2), 412–421. doi:10.1519/R-16808.1
4. OpenPowerlifting Project. (2026). Open database of powerlifting competition results. Retrieved from openpowerlifting.org.