The Wilks Coefficient
How powerlifters compare a 150 lb lifter to a 250 lb lifter fairly.
Wilks normalises total lifted against bodyweight so absolute numbers become relative scores that rank across weight classes.
Absolute strength favours bigger lifters — a 250 lb lifter will almost always out-squat a 150 lb lifter. But who is stronger for their size? The Wilks coefficient answers that. It runs bodyweight through a polynomial fit to competitive powerlifting data and multiplies against your total. Same Wilks score means same relative strength, regardless of weight class.
Quick answer
Wilks normalises total lifted against bodyweight so absolute numbers become relative scores that rank across weight classes.
Key points
- ▸ Score = total lifted × Wilks coefficient. Wilks coefficient is derived from a 5th-order polynomial of bodyweight.
- ▸ The polynomial captures the square-cube law: strength scales as cross-section (squared), mass scales as volume (cubed), so relative strength decays with size.
- ▸ Approximate bands: 200-299 intermediate, 300-399 advanced, 400+ elite, 500+ world-class.
- ▸ Gender-specific coefficients exist because male and female strength-to-mass relationships differ across the bodyweight spectrum.
- ▸ Wilks 2020 replaced the original 1994 formula with updated data and better extrapolation at the extremes.
Examples
- 180 lb male · 1350 lb totalWilks ≈ 392 — Advanced. Adding 50 lb to total moves the score ~15 points; adding 10 lb of bodyweight moves it ~3 points down.
- 130 lb female · 750 lb totalWilks ≈ 435 — Elite. Lighter-weight lifters get a larger multiplier, reflecting relative strength.
- Same 400 Wilks at 150 lb vs 250 lbThe 150 lb lifter might total 1100; the 250 lb lifter totals 1500. Different numbers, identical relative output.
When to use which tool
Related
- Strength-to-Weight Efficiency · WilksWilks coefficient — the powerlifting gold-standard for comparing lifters across bodyweight classes.
- Interpreting Your Wilks ScoreWhere you sit in the novice-intermediate-advanced-elite spectrum.
- Wilks Formula PitfallsThe conditions where Wilks over- or under-states relative strength.
- The Brzycki 1RM FormulaEstimate a true one-rep max from a submax set without risking a heavy single.
Frequently asked questions
› Is Wilks better than IPF Points? Comparison
IPF Points is the newer official IPF standard; Wilks remains dominant elsewhere. Numerical values differ, rankings correlate tightly. Pick whichever matches your federation and stay consistent.
› Does Wilks apply to single lifts?
Yes — enter that single lift where the calculator asks for total. The bands shift (a 400 squat-only Wilks is different from a 400 total Wilks), but the relative-strength normalisation still holds.
› How should I use this guide with a Kefiw tool? How-to
Use the guide as the plan and the linked Kefiw tool as the check. Read the steps first, try the move manually, then use the tool to compare outputs, catch edge cases, and decide whether the result actually fits your task.
› What mistake do tool guides help avoid? Troubleshooting
Tool guides help avoid using a utility mechanically without understanding what you are trying to accomplish. Most word, writing, and text utilities are fast, but speed can hide context mistakes. Know whether you are solving a puzzle, cleaning copy, drafting a line, or checking a rule.
› Can a tool guide help me learn the skill? How-to
A tool guide can help you learn if you pause before accepting the output and ask why it worked. Compare your first guess with the tool result, look for the rule or pattern, and repeat that review. Passive copying solves one task; active review builds the skill.