Strength calculator
Sinclair calculator
Score an Olympic weightlifting total across bodyweights with the IWF Sinclair coefficient for the 2025–2028 quadrennium. Free, instant, no sign-up.
The ratio usually names the problem — the coach turns it into a week of work.
What is the Sinclair coefficient?
The Sinclair coefficient answers one question: what would this lifter total if they were a superheavyweight of exactly the same ability? Multiply a competition total by the coefficient for that bodyweight and you get a Sinclair total — a bodyweight-neutral score that lets a 55 kg lifter and a 110 kg lifter be ranked on the same list. It is the number the IWF uses for best-lifter awards and the one every weightlifting meet report quotes.
How the Sinclair formula works
The formula, devised by the Canadian statistician Roy Sinclair, is 10^(A · (log₁₀(bodyweight ÷ b))²), where b is the bodyweight of the world-record holder in the heaviest category and A is a fitted curvature constant. Below b the coefficient rises as bodyweight falls; at or above b it is exactly 1.0, because there is no heavier class to project a lifter into. For the 2025–2028 Olympiad the IWF publishes A = 0.700767819 with b = 201.159 kg for men, and A = 0.674107991 with b = 163.918 kg for women.
Why the coefficients change every four years
Sinclair constants are re-derived from world-record totals after each Olympic Games, so they track the sport as it actually is rather than as it was. The current set was refitted after Paris 2024 and the bodyweight-category change that took effect in June 2025, which is why a Sinclair total from 2023 is not directly comparable to one calculated today. When you quote a score, quote the quadrennium with it — the difference between cycles runs to several kilograms at the light end.
Reading the snatch-to-clean-&-jerk ratio
A well-balanced lifter snatches roughly 78–82 % of their best clean & jerk. Sitting well below that usually points at the snatch itself — turnover speed, overhead stability, or confidence under a heavy bar — rather than at raw strength. Sitting well above it is the opposite tell: the snatch is technically sound and the jerk, or plain leg strength, is the limiter. Track the ratio alongside the Sinclair total and you will see which one is actually paying for your score.