How is a Wilks score calculated?
A Wilks score takes your powerlifting total and multiplies it by a coefficient derived from a 5th-degree polynomial of your bodyweight, so lifters of different sizes can be compared on one scale. Here is the exact formula, the published male constants, and a worked example that lands on 398.8.
Open the Wilks calculatorWant the number now? The Wilks Calculator applies the exact polynomial below to your bodyweight and total, in kg or lb, and returns the coefficient and score.
What a Wilks score is for
Powerlifting totals cannot be compared directly across bodyweights: a 60 kg lifter and a 120 kg lifter who both total 500 kg have not performed equally relative to their size. The Wilks formula, developed by Robert Wilks of Powerlifting Australia, produces a single normalising coefficient so that a lighter lifter's total is scaled up and a heavier lifter's total is scaled down toward a common reference. Multiplying your total by that coefficient gives the Wilks score, a size-adjusted comparison number.
The formula
The calculation has two steps. First the coefficient is found from a fifth-degree polynomial in bodyweight; then the coefficient multiplies the total lifted.
- x
- bodyweight in kilograms (the formula is calibrated in kg)
- total_lifted_kg
- the sum of best squat, bench and deadlift, in kilograms
- a…f
- the six sex-specific published polynomial constants
- 500
- the fixed numerator that sets the overall scale of the score
The male polynomial constants
The constants are sex-specific. The published Original Wilks values for men are:
| Constant | Male value |
|---|---|
a | −216.0475144 |
b | 16.2606339 |
c | −0.002388645 |
d | −0.00113732 |
e | 7.01863 × 10⁻⁶ |
f | −1.291 × 10⁻⁸ |
Women use a different set of six constants; the Wilks Calculator holds both. The important point is that the coefficient depends only on bodyweight and sex — the total lifted never enters the polynomial.
Kilograms come first
The Wilks polynomial is strictly calibrated in kilograms. If you train and
compete in pounds, both your bodyweight and your total must be converted to kilograms
(1 kg = 2.20462262 lb) before the formula is evaluated. Plugging pounds
straight into the polynomial produces a meaningless number.
Worked example: 83 kg male, 600 kg total
- Bodyweight
x = 83.0 kg. - Evaluate the 5th-degree polynomial with the male constants:
Denominator = 752.228. - Coefficient:
500 / 752.228 = 0.66469. - Multiply the total by the coefficient:
600 × 0.66469 = 398.81. - Final score: 398.8 Wilks.
This is the same worked example the Wilks Calculator uses as its default, so you can reproduce every step and confirm the coefficient of 0.6647 yourself.
Wilks, Wilks-2 and comparability
A revised set of coefficients, Wilks-2 (a 2020 revision), also circulates alongside the original. The two use the same overall structure but different fitted constants, so they produce slightly different numbers. That leads to the single most important rule of reading any of these scores: a Wilks score only means something when compared against another score from the same coefficient set and version. Comparing an Original Wilks figure with a Wilks-2 figure — or with a DOTS or IPF GL number — is comparing different scales.
What a Wilks score does not tell you
The Wilks formula is a population-fitted comparison tool. It assumes the total you enter is a real, legally judged total; it cannot know whether your squat hit depth, whether the bench was paused, or whether the lifts were performed under any federation's technical rules. It is also only as accurate as the fit at your bodyweight, and it says nothing about drug-testing status. Treat the score as a comparison number, not a certificate of performance. Note too that the IPF itself replaced Wilks with GL points in 2019, so IPF results are no longer ranked on Wilks.
Frequently asked questions
Does the total go inside the polynomial?
No. The polynomial uses bodyweight only. The total lifted is multiplied by the resulting coefficient afterwards, so two lifters at the same bodyweight and sex share the same coefficient.
Do I convert pounds before or after?
Before. Both bodyweight and total are converted to kilograms first (1 kg = 2.20462262 lb), because the polynomial constants are calibrated in kilograms.
Why do two calculators give me slightly different Wilks numbers?
They are probably using different coefficient sets — Original Wilks versus the Wilks-2 (2020) revision. A score only compares against another score from the same set and version.
Related tools and reading
Wilks Calculator
Enter bodyweight and total in kg or lb and see the coefficient and Wilks score instantly.
ReadWhat is a good Wilks score?
Where common community benchmarks sit, and why the bands are not an official classification.
Sources
- Robert Wilks (Powerlifting Australia), the Wilks formula and published sex-specific polynomial coefficients. Checked 23 Aug 2026.
- International Powerlifting Federation, replacement of the Wilks formula with IPF GL points in 2019. Checked 23 Aug 2026.