How this calculator works
Powerlifting totals rise with body weight, so a heavier lifter usually lifts more without being relatively stronger. The Wilks formula corrects for that by converting the total into a coefficient based on body weight. The coefficient is 500 divided by a fifth-order polynomial in body weight, and the score is the total multiplied by the coefficient. A score near 300 is a solid recreational level, 400 is strong, and the best lifters in a weight class exceed 450 to 500. The polynomial differs for men and women because the relationship between body weight and performance is different.
Formula
Wilks coefficient = 500 / (a + b x + c x squared + d x cubed + e x to the fourth + f x to the fifth), where x is body weight in kilograms. Wilks score = total in kilograms x coefficient. The coefficients for men are -216.0475144, 16.2606339, -0.002388645, -0.00113732, 7.01863e-6 and -1.291e-8. For women they are 594.31747775582, -27.23842536447, 0.82112226871, -0.00930733913, 4.731582e-5 and -9.054e-8.
Worked example
An 80 kg man with a 500 kg total uses x = 80. The polynomial evaluates to about 210.06, so the coefficient is 500 / 210.06 = 2.3803. The coefficient is 500 / 732.4 = 0.6827, so the score is 500 x 0.6827 = 341. A 60 kg woman with a 300 kg total has a coefficient of about 1.1149, giving 300 x 1.1149 = 334.
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Frequently asked questions
What is a good Wilks score?
For recreational lifters, 250 to 350 is common. A score around 400 is strong, and 450 or more is competitive at a high level. The exact benchmark depends on age, sex and the federation, so compare like with like.
Is Wilks still used?
The original Wilks formula was the IPF standard until 2018, when it moved to the GL formula. Many federations and databases still publish Wilks scores because they allow comparisons with older results. Use the same formula for every lifter in a comparison.
Why does the formula use a fifth-order polynomial?
Body weight and performance do not follow a simple straight line. A higher-order curve captures the way the relationship changes across the weight range, especially at the light and heavy ends. The coefficients were fitted to competition data.
Does the score work for a single lift?
Yes, you can enter a single lift as the total, but the score is then a single-lift comparison rather than a full powerlifting total. Most published benchmarks assume the three-lift total, so a single-lift score is not directly comparable.