This Wilks calculator measures the strength of a powerlifter to be used for comparison with other powerlifters based on body weight and lifted weight.
How does the Wilks calculator work?
This is a health tool that helps compare the strength of a powerlifter against other powerlifters, even when different weight categories are involved.
This formula is used by the International Powerlifting Federation and Powerlifting Australia.
The three variables used in the Wilks score calculator are:
■ Body weight – measured in either kilograms or pounds;
■ Gender – there are different variables used in the Wilks coefficient, according to gender;
■ Weight lifted - measured in either kilograms or pounds.
The formula used to calculate the Wilks coefficient is:
Wilks coefficient = 500 / (a + bx² +cx³ +dx⁴ +ex⁵ +fx⁶)
Where:
x = Body weight of the lifter measured in kilograms.
The following table introduces the a to f values for the male and female gender:
| Values | Male | Female |
| a | -216.0475144 | 594.31747775582 |
| b | 16.2606339 | -27.23842536447 |
| c | -0.002388645 | 0.82112226871 |
| d | -0.00113732 | -0.00930733913 |
| e | 7.01863E-06 | 4.731582E-05 |
| f | -1.291E-08 | -9.054E-08 |
In order to transform the coefficient to points, the Wilks coefficient is multiplied by the weight lifted (in kilograms):
Wilks score (points) = Wilks coefficient * Weight lifted in kilograms
Taking the case of a male weightlifter with a body weight of 98 kg and the weight lifted of 215 kg, the result is 131.924 Wilks points.
There are other calculators that can be used for weight lifting, such as the 1RM calculator or tools that determine the muscle mass index in bodybuilder, such as the Fat Free Mass Index (FFMI).
About the Wilks formula
This method was created by Robert Wilks, the CEO of Powerlifting Australia. The formula was further validated based on the female and male world record holders in the IPF’s 1996 respectively 1997 World Championships.
It was found that there is no bias for men's or women's bench press and total. However, there is a favorable bias toward female intermediate weight class lifters in the women's squat.
The formula not only compares weightlifters, but can also compare different gender weightlifters and across different weight categories.
Wilks coefficient addresses the imbalance whereby lighter lifters tend to have a greater power to weight ratio compared to heavier lifters.
Reference
Vanderburgh PM, Batterham AM. (1999) Validation of the Wilks Powerlifting Formula. Medicine and Science in Sports and Exercise; 31(12):1869-1875.
18 May, 2017