The Wilks calculator allows you to estimate your weightlifting abilities and compare yourself with other lifters, regardless of their body weight or sex. Unlike the bench press calculator, it is not generally used to track your progress, but to decide on which weightlifter is better (even though they compete in different divisions). Read on the article to learn what is the Wilks formula and how to apply it correctly. Moreover, you will find some information about weightlifting as an exercise, Olympic weightlifting and the equipment like e.g. weightlifting shoes.

What is the Wilks coefficient?

The Wilks coefficient was introduced to make it possible to compare strengths of powerlifters despite their different capabilities resulting from body structure. During competitions, weightlifters are divided into categories according to their body weight and sex. The Wilks coefficient allows for comparison of the lifters across all categories.

The formula was derived by Robert Wilks, CEO of Powerlifting Australia.

The Wilks formula

There is one universal formula that can be applied to all weightlifters, both male and female. The only thing that is different are the coefficients used in the equation.

The Wilks formula is:

Wilks coefficient = W * 500 / (a + bx +cx² +dx³ +ex⁴ +fx⁵)

where W is the maximum weight lifted (in kilograms), x is the body weight of the lifter, and letters a to f denote coefficients.

Coefficients for men are:

  • a = -216.0475144
  • b = 16.2606339
  • c = -0.002388645
  • d = -0.00113732
  • e = 7.01863E-06
  • f = -1.291E-08

Coefficients for women are:

  • a = 594.31747775582
  • b = -27.23842536447
  • c = 0.82112226871
  • d = -0.00930733913
  • e = 4.731582E-05
  • f = -9.054E-08

How to use the Wilks calculator?

Let's say you want to compare the weightlifting capabilities of two different weightlifters. The first one is a female champion who weighs 48 kg and competes in the lowest body weight division. The second is a man who weighs 107 kg and competes in the highest body weight division.

  1. Find out what the female lifter's personal record was. Let's say it was 94 kg.
  2. Find out what the male lifter's personal record was. Let's say it was 208 kg.
  3. Calculate the Wilks coefficient for the female lifter, using our Wilks calculator. You will be left with the result of 124.5.
  4. Repeat the above step for the male lifter. You will obtain 123.5 as a result.
  5. Surprisingly, the female weightlifter has scored higher. That means that even though she can lift less kilograms, she is objectively better than the male lifter.


Weightlifting is a discipline of strength athletics, where contests consist of single lifting of a barbell with plates. It is also a popular power training exercise, performed in almost every gym in the world. Weightlifting uses a weight load made of steel or cast-iron. The barbell is a steel bar or rode to which iron disk weights are attached at each end on a revolving sleeve. Some others activities like training, bodybuilding and powerlifting also use weights.

The history of weightlifting is quite long. For many prehistoric tribes, lifting of a special rock was a test of manhood. Some regions of Germany, Switzerland, Spain, and Montenegro still practice competitive stone lifting.

Modern weightlifting competitions were founded in the 18th and 19th century. They started as shows performed in circuses and theaters. First international weightlifting competition took place in London in 1891, and four years later, it appeared at the Olympic Games (1896). In 2000 year the International Olympic Committee has added a weightlifting competition for women to the Olympic Games program. International Weightlifting Federation (IWF) controls the weightlifting sport, since its foundation in year 1905. IWF has the headquarters in Budapest, Hungary.

Olympic weightlifting

Two lift competitions are held at the modern Olympic Games. First one is the snatch, second is the clean and jerk. The snatch is a wide grip, one move lift. The clean and jerk is a close grip, two-move lift. Each athlete has three attempts in each style; two highest, successful lifts (within a bodyweight category) are taken into account for the overall result.

Bodyweight categories are different for male and female competitors. You can see them below:

Men's weight classes:

  • 56 kg (123 lb)
  • 62 kg (137 lb)
  • 69 kg (152 lb)
  • 77 kg (170 lb)
  • 85 kg (187 lb)
  • 94 kg (207 lb)
  • 105 kg (231 lb)
  • 105 kg and over (231 lb+)

Women's weight classes:

  • 48 kg (106 lb)
  • 53 kg (117 lb)
  • 58 kg (128 lb)
  • 63 kg (139 lb)
  • 69 kg (152 lb)
  • 75 kg (165 lb)
  • 90 kg (198 lb)
  • 90 kg and over (198 lb+)

While other strength sports tests athlete's limit strength, weightlifting tests human explosive strength (aspects of ballistic limits). The lifts are executed faster, with more mobility and a greater range of motion during their execution than other strength movements.

Weightlifting shoes

Let's take a closer look at the equipment used while weightlifting. Few useful items make this discipline safer and more comfortable for an athlete.

  1. Barbell - men's Olympic barbell weighs 20 kg (44 lbs) with a shaft diameter of 28 mm and a length of 2200 mm. A women's Olympic barbell weights 15 kg (33 lbs) and has a shaft diameter of 25 mm with a length of 2010 mm.

  2. Plates - Olympic plates have standardized coloring for particular weights:

Colour 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 2.5 5.51
blue 2 4.41
yellow 1.5 3.31
green 1 2.20
white 0.5 1.10
  1. Collar - secures the plates on the bar on each sleeve. It weighs 2.5 kg each.

  2. Belt - it helps to increase intra-abdominal pressure.

  3. Chalk - improves the grip between hands and the barbell by eliminating sweat.

  4. Tape - applied e.g. on the wrists and other body parts to prevent injuries and reduce pain.

  5. Shoes - designed with a raised heel of 0.5" to 1.5" and one or two metatarsal straps. The raised heel allows for a deeper squat under the bar and helps to maintain an upright torso. Rigid soles of the shoes help to resist compression under heavy loads.

Bogna Haponiuk and Filip Derma.

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