Free Wilks Calculator

Understanding the Wilks Coefficient Calculator

The Wilks Coefficient Calculator is a powerful tool for weightlifting enthusiasts and competitive powerlifters who need an objective method for strength comparison regardless of differences in body weight or gender. By producing a standardized score, this weightlifting strength comparison tool allows athletes across different competition divisions to be evaluated on a level playing field. Unlike a one-rep max calculator, which tracks individual progress, the Wilks Score Calculator focuses on comparing the relative performance of different lifters.

Robert Wilks, the former CEO of Powerlifting Australia, created the Wilks coefficient to address the challenge of comparing lifters in varied weight classes. The coefficient adjusts the total weight lifted according to the athlete’s body weight and sex, yielding a single number that indicates relative strength.

The Wilks Formula and Coefficients

The calculation uses a lifters' total weight lifted ($W$, in kilograms) and their body weight ($x$, in kilograms). A polynomial expression with sex-specific coefficients generates a factor that is then multiplied by $W$:

$$\text{Wilks Score} = W \times (a + b x + c x^{2} + d x^{3} + e x^{4} + f x^{5})$$

The coefficients ($a, b, c, d, e, f$) are different for men and women, as shown below.

Men’s coefficients

Coefficient	Value
$a$	$-216.0475144$
$b$	$16.2606339$
$c$	$-0.002388645$
$d$	$-0.00113732$
$e$	$7.01863 \times 10^{-6}$
$f$	$-1.291 \times 10^{-8}$

Women’s coefficients

Coefficient	Value
$a$	$594.31747775582$
$b$	$-27.23842536447$
$c$	$0.82112226871$
$d$	$-0.00930733913$
$e$	$4.731582 \times 10^{-5}$
$f$	$-9.054 \times 10^{-8}$

How to Use the Wilks Score Calculator

Using this free Wilks calculator online is straightforward. Consider two lifters: a female athlete weighing 48 kg who lifts a personal best of 94 kg, and a male athlete weighing 107 kg who lifts 208 kg. Input each lifter’s sex, body weight, and total weight lifted into the calculator.

• For the female lifter, the Wilks score is 124.5.
• For the male lifter, the Wilks score is 123.5.

Although the male lifter lifted more absolute weight, the female lifter achieved a higher Wilks score, meaning she demonstrated greater relative strength. This example highlights why Wilks is an essential metric for weightlifting strength comparison.

Weightlifting as a Sport and Exercise

Weightlifting, also known as Olympic weightlifting, is a discipline where athletes lift a barbell loaded with weight plates in a single movement (snatch) or two movements (clean and jerk). It is a fundamental power training exercise practiced worldwide.

The sport has ancient origins—many cultures tested strength by lifting stones. Modern weightlifting competitions began in the 18th and 19th centuries as circus and theatre acts. The first international weightlifting championship was held in London in 1891, and the sport entered the Olympic Games in 1896. Women’s weightlifting was added to the Olympic program in 2000. The International Weightlifting Federation (IWF), founded in 1905 and headquartered in Budapest, governs the sport.

Olympic Weightlifting Movements

Two lifts are contested in Olympic weightlifting: the snatch (a wide-grip, one-motion lift) and the clean and jerk (a close-grip, two-motion lift). Each athlete receives three attempts per lift; the two heaviest successful lifts within their body weight category are combined for the final score.

Body weight categories differ by sex. The standard classes are:

Men’s weight class	Women’s weight class
56 kg (123 lb)	48 kg (106 lb)
62 kg (137 lb)	53 kg (117 lb)
69 kg (152 lb)	58 kg (128 lb)
77 kg (170 lb)	63 kg (139 lb)
85 kg (187 lb)	69 kg (152 lb)
94 kg (207 lb)	75 kg (165 lb)
105 kg (231 lb)	90 kg (198 lb)
+105 kg (+231 lb)	+90 kg (+198 lb)

Equipment Used in Weightlifting

Proper gear enhances safety and performance. Key items include:

• Barbell: The men’s Olympic barbell weighs 20 kg, with a shaft diameter of 28 mm and length of 2200 mm. The women’s barbell weighs 15 kg, with a 25 mm shaft diameter and 2010 mm length.
• Weight plates: Olympic plates follow a standardized color scheme:

Color	Weight (kg)	Weight (lb)
Red	25	55.12
Blue	20	44.09
Yellow	15	33.07
Green	10	22.05
White	5	11.02
Red (small)	2.5	5.51
Blue (small)	2	4.41
Yellow (small)	1.5	3.31
Green (small)	1	2.20
White (small)	0.5	1.10

• Collar: Each collar weighs 2.5 kg and secures the plates on the bar.
• Belt: Helps increase intra‑abdominal pressure for stability.
• Chalk: Improves grip by absorbing sweat.
• Tape: Applied to wrists or other areas to prevent injuries and reduce pain.
• Shoes: Weightlifting shoes have a raised heel (0.5–1.5 inches) and one or two metatarsal straps. The elevated heel allows for a deeper squat under the bar and helps maintain an upright torso, while the rigid sole resists compression under heavy loads.

Whether you are an experienced powerlifter or a beginner curious about comparing your strength, this Wilks Coefficient Calculator offers a reliable way to evaluate your performance relative to others. Its standardized scoring system makes it an indispensable tool for the weightlifting community.